diff --git a/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java b/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
index 58c949bfaf38..b568d320d05f 100644
--- a/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
+++ b/spring-web/src/main/java/org/springframework/web/server/session/InMemoryWebSessionStore.java
@@ -42,6 +42,7 @@
  *
  * @author Rossen Stoyanchev
  * @author Rob Winch
+ * @author Mengqi Xu
  * @since 5.0
  */
 public class InMemoryWebSessionStore implements WebSessionStore {
@@ -51,6 +52,8 @@ public class InMemoryWebSessionStore implements WebSessionStore {
 
 	private int maxSessions = 10000;
 
+	private Duration defaultMaxIdleTime = Duration.ofMinutes(30);
+
 	private Clock clock = Clock.system(ZoneId.of("GMT"));
 
 	private final Map<String, InMemoryWebSession> sessions = new ConcurrentHashMap<>();
@@ -78,6 +81,23 @@ public int getMaxSessions() {
 		return this.maxSessions;
 	}
 
+	/**
+	 * Set the default maximum idle time for sessions.
+	 * <p>By default, set to 30 minutes.
+	 * @param maxIdleTime the default max idle time
+	 */
+	public void setDefaultMaxIdleTime(Duration maxIdleTime) {
+		Assert.notNull(maxIdleTime, "maxIdleTime is required");
+		this.defaultMaxIdleTime = maxIdleTime;
+	}
+
+	/**
+	 * Return the default maximum idle time for sessions.
+	 */
+	public Duration getDefaultMaxIdleTime() {
+		return this.defaultMaxIdleTime;
+	}
+
 	/**
 	 * Configure the {@link Clock} to use to set the {@code lastAccessTime} on
 	 * every created session and to calculate if the session has expired.
@@ -119,7 +139,7 @@ public Mono<WebSession> createWebSession() {
 		Instant now = this.clock.instant();
 		this.expiredSessionChecker.checkIfNecessary(now);
 
-		return Mono.<WebSession>fromSupplier(() -> new InMemoryWebSession(now))
+		return Mono.<WebSession>fromSupplier(() -> new InMemoryWebSession(now, this.defaultMaxIdleTime))
 				.subscribeOn(Schedulers.boundedElastic())
 				.publishOn(Schedulers.parallel());
 	}
@@ -180,14 +200,15 @@ private class InMemoryWebSession implements WebSession {
 
 		private volatile Instant lastAccessTime;
 
-		private volatile Duration maxIdleTime = Duration.ofMinutes(30);
+		private volatile Duration maxIdleTime;
 
 		private final AtomicReference<State> state = new AtomicReference<>(State.NEW);
 
 
-		public InMemoryWebSession(Instant creationTime) {
+		public InMemoryWebSession(Instant creationTime, Duration maxIdleTime) {
 			this.creationTime = creationTime;
 			this.lastAccessTime = this.creationTime;
+			this.maxIdleTime = maxIdleTime;
 		}
 
 		@Override