diff --git a/benchmark/src/main/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20.java b/benchmark/src/main/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20.java
index b2444401d5..17c39dd61a 100644
--- a/benchmark/src/main/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20.java
+++ b/benchmark/src/main/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20.java
@@ -2,6 +2,7 @@
 
 import com.alibaba.fastjson2.JSON;
 import com.alibaba.fastjson2.JSONB;
+import com.alibaba.fastjson2.JSONWriter;
 import com.alibaba.fastjson2.benchmark.primitves.vo.BigInteger20Field;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.gson.Gson;
@@ -49,6 +50,12 @@ public void fastjson2(Blackhole bh) {
         );
     }
 
+    public void fastjson2_array_bytes(Blackhole bh) {
+        bh.consume(
+                JSON.toJSONBytes(bean, JSONWriter.Feature.BeanToArray)
+        );
+    }
+
     @Benchmark
     public void jsonb(Blackhole bh) {
         bh.consume(
diff --git a/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20Test.java b/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20Test.java
index 2157f006fc..e0f67d945e 100644
--- a/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20Test.java
+++ b/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/primitves/BigInteger20Test.java
@@ -12,9 +12,24 @@ public static void fastjson2() {
                 benchmark.fastjson2(BH);
             }
             long millis = System.currentTimeMillis() - start;
-            System.out.println("BigDecimal20-fastjson2 : " + millis);
+            System.out.println("BigInteger20-fastjson2 : " + millis);
 
-            // zulu8.68.0.21 : 367
+            // zulu8.68.0.21 : 367 246
+            // zulu11.52.13 :
+            // zulu17.32.13 :
+        }
+    }
+
+    public static void fastjson2_array_bytes() {
+        for (int j = 0; j < 10; j++) {
+            long start = System.currentTimeMillis();
+            for (int i = 0; i < 1000 * 1000; ++i) {
+                benchmark.fastjson2_array_bytes(BH);
+            }
+            long millis = System.currentTimeMillis() - start;
+            System.out.println("BigInteger20-fastjson2_array_bytes : " + millis);
+
+            // zulu8.68.0.21 : 1166
             // zulu11.52.13 :
             // zulu17.32.13 :
         }
@@ -27,9 +42,9 @@ public static void jsonb() {
                 benchmark.jsonb(BH);
             }
             long millis = System.currentTimeMillis() - start;
-            System.out.println("BigDecimal20-jsonb : " + millis);
+            System.out.println("BigInteger20-jsonb : " + millis);
 
-            // zulu8.62.0.19 :
+            // zulu8.62.0.19 : 280
             // zulu11.52.13 :
             // zulu17.40.19 :
         }
@@ -42,8 +57,8 @@ public static void jackson() throws Exception {
                 benchmark.jackson(BH);
             }
             long millis = System.currentTimeMillis() - start;
-            System.out.println("BigDecimal20-jackson : " + millis);
-            // zulu8.62.0.19 :
+            System.out.println("BigInteger20-jackson : " + millis);
+            // zulu8.62.0.19 : 1150
             // zulu11.52.13 :
             // zulu17.32.13 :
         }
@@ -56,8 +71,8 @@ public static void wastjson() throws Exception {
                 benchmark.wastjson(BH);
             }
             long millis = System.currentTimeMillis() - start;
-            System.out.println("BigDecimal20-wastjson : " + millis);
-            // zulu8.62.0.19 :
+            System.out.println("BigInteger20-wastjson : " + millis);
+            // zulu8.62.0.19 : 1104
             // zulu11.52.13 :
             // zulu17.32.13 :
         }
@@ -65,11 +80,9 @@ public static void wastjson() throws Exception {
 
     public static void main(String[] args) throws Exception {
 //        fastjson2();
+//        fastjson2_array_bytes();
         jsonb();
-//        hessian();
-//        fury();
 //        jackson();
 //        wastjson();
-//        kryo();
     }
 }
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
index 5d76d52d2f..326192aa16 100644
--- a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
+++ b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF16.java
@@ -18,6 +18,7 @@
 import static com.alibaba.fastjson2.JSONWriter.Feature.*;
 import static com.alibaba.fastjson2.util.IOUtils.*;
 import static com.alibaba.fastjson2.util.JDKUtils.*;
+import static com.alibaba.fastjson2.util.TypeUtils.isInt64;
 
 class JSONWriterUTF16
         extends JSONWriter {
@@ -1233,6 +1234,11 @@ public final void writeBigInt(BigInteger value, long features) {
             return;
         }
 
+        if (isInt64(value) && features == 0) {
+            writeInt64(value.longValue());
+            return;
+        }
+
         String str = value.toString(10);
 
         features |= context.features;
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
index efb0f028ab..e1c6440109 100644
--- a/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
+++ b/core/src/main/java/com/alibaba/fastjson2/JSONWriterUTF8.java
@@ -17,6 +17,7 @@
 import static com.alibaba.fastjson2.JSONWriter.Feature.*;
 import static com.alibaba.fastjson2.util.IOUtils.*;
 import static com.alibaba.fastjson2.util.JDKUtils.*;
+import static com.alibaba.fastjson2.util.TypeUtils.isInt64;
 
 class JSONWriterUTF8
         extends JSONWriter {
@@ -2468,6 +2469,11 @@ public final void writeBigInt(BigInteger value, long features) {
             return;
         }
 
+        if (isInt64(value) && features == 0) {
+            writeInt64(value.longValue());
+            return;
+        }
+
         String str = value.toString(10);
 
         if (((context.features | features) & Feature.BrowserCompatible.mask) != 0
diff --git a/core/src/main/java/com/alibaba/fastjson2/util/JDKUtils.java b/core/src/main/java/com/alibaba/fastjson2/util/JDKUtils.java
index dce4add3d1..71518cf775 100644
--- a/core/src/main/java/com/alibaba/fastjson2/util/JDKUtils.java
+++ b/core/src/main/java/com/alibaba/fastjson2/util/JDKUtils.java
@@ -6,6 +6,7 @@
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.math.BigDecimal;
+import java.math.BigInteger;
 import java.nio.ByteOrder;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -27,6 +28,7 @@ public class JDKUtils {
     public static volatile boolean FIELD_STRING_VALUE_ERROR;
 
     public static final long FIELD_DECIMAL_INT_COMPACT_OFFSET;
+    public static final long FIELD_BIGINTEGER_MAG_OFFSET;
 
     public static final Field FIELD_STRING_CODER;
     public static final long FIELD_STRING_CODER_OFFSET;
@@ -183,6 +185,17 @@ public class JDKUtils {
             FIELD_DECIMAL_INT_COMPACT_OFFSET = fieldOffset;
         }
 
+        {
+            long fieldOffset = -1;
+            try {
+                Field field = BigInteger.class.getDeclaredField("mag");
+                fieldOffset = UNSAFE.objectFieldOffset(field);
+            } catch (Throwable ignored) {
+                // ignored
+            }
+            FIELD_BIGINTEGER_MAG_OFFSET = fieldOffset;
+        }
+
         BIG_ENDIAN = ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN;
 
         BiFunction<char[], Boolean, String> stringCreatorJDK8 = null;
diff --git a/core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java b/core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java
index a50ed4574c..bc949357c1 100644
--- a/core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java
+++ b/core/src/main/java/com/alibaba/fastjson2/util/TypeUtils.java
@@ -19,8 +19,8 @@
 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
 import java.util.function.*;
 
-import static com.alibaba.fastjson2.util.JDKUtils.FIELD_DECIMAL_INT_COMPACT_OFFSET;
-import static com.alibaba.fastjson2.util.JDKUtils.UNSAFE;
+import static com.alibaba.fastjson2.util.JDKUtils.*;
+import static com.alibaba.fastjson2.util.JDKUtils.FIELD_BIGINTEGER_MAG_OFFSET;
 import static java.lang.invoke.MethodType.methodType;
 
 public class TypeUtils {
@@ -1883,6 +1883,12 @@ public static boolean isInt32(BigInteger value) {
     }
 
     public static boolean isInt64(BigInteger value) {
+        if (FIELD_BIGINTEGER_MAG_OFFSET != -1) {
+            int[] mag = (int[]) UNSAFE.getObject(value, FIELD_BIGINTEGER_MAG_OFFSET);
+            if (mag.length == 1 || (mag.length == 2 && mag[0] >= 0)) {
+                return true;
+            }
+        }
         return value.compareTo(BIGINT_INT64_MIN) >= 0 && value.compareTo(BIGINT_INT64_MAX) <= 0;
     }