diff --git a/pkg/hostman/guestman/guestman.go b/pkg/hostman/guestman/guestman.go
index dd8d51f8af..f4fb096431 100644
--- a/pkg/hostman/guestman/guestman.go
+++ b/pkg/hostman/guestman/guestman.go
@@ -258,17 +258,23 @@ func (m *SGuestManager) InitQemuMaxCpus(machineCaps []monitor.MachineInfo, kvmMa
 
 func (m *SGuestManager) InitQemuMaxMems(maxMems uint) {
 	if m.host.IsX8664() {
-		if maxMems > arch.X86_MAX_MEM_MB {
+		if options.HostOptions.GuestMaxMemSizeMb > 0 {
+			arch.X86_MAX_MEM_MB = uint(options.HostOptions.GuestMaxMemSizeMb)
+		} else if maxMems > arch.X86_MAX_MEM_MB {
 			arch.X86_MAX_MEM_MB = maxMems
 		}
 	}
 	if m.host.IsAarch64() {
-		if maxMems > arch.ARM_MAX_MEM_MB {
+		if options.HostOptions.GuestMaxMemSizeMb > 0 {
+			arch.ARM_MAX_MEM_MB = uint(options.HostOptions.GuestMaxMemSizeMb)
+		} else if maxMems > arch.ARM_MAX_MEM_MB {
 			arch.ARM_MAX_MEM_MB = maxMems
 		}
 	}
 	if m.host.IsRiscv64() {
-		if maxMems > arch.RISCV_MAX_MEM_MB {
+		if options.HostOptions.GuestMaxMemSizeMb > 0 {
+			arch.RISCV_MAX_MEM_MB = uint(options.HostOptions.GuestMaxMemSizeMb)
+		} else if maxMems > arch.RISCV_MAX_MEM_MB {
 			arch.RISCV_MAX_MEM_MB = maxMems
 		}
 	}
diff --git a/pkg/hostman/options/options.go b/pkg/hostman/options/options.go
index f9469d2788..26d1b72cdb 100644
--- a/pkg/hostman/options/options.go
+++ b/pkg/hostman/options/options.go
@@ -245,6 +245,8 @@ type SHostOptions struct {
 	EnableQemuDebugLog  bool   `help:"enable qemu debug logs" default:"false"`
 	ResetDiskTmpDir     string `help:"auto reset disk after guest shutdown will write disk to tmpdir"`
 
+	GuestMaxMemSizeMb int `help:"guest maximal mem size, default 0 is not set" default:"0"`
+
 	// container related endpoint
 	// EnableContainerRuntime   bool   `help:"enable container runtime" default:"false"`
 	ContainerRuntimeEndpoint                 string `help:"endpoint of container runtime service" default:"unix:///var/run/onecloud/containerd/containerd.sock"`