A method for cross-service-zone communication performed by a system comprising a gateway, a service zone manager, a first server, a second server, a first cloud management function and a second cloud management function, the method comprising: • when a first virtual machine on the first server needs to send a packet to a second virtual machine on the second server, determining, by the first server, through searching, whether a routing table of a same tenant to which the first virtual machine and the second virtual machine belong exists on the first server (step 405), wherein the first virtual machine is located in a first service zone being managed by the first cloud management function and the second virtual machine is located in a second service zone being managed by the second cloud management function, and the packet comprises a subnet identifier of the first server; • when the routing table of the tenant does not exist on the first server, sending, by the first virtual machine on first server, the packet to the gateway (step 407); • receiving, by the gateway, the packet destined for the second virtual machine on the second server and sent by the first virtual machine on the first server; • acquiring, by the gateway, the routing table of the tenant, to which the first and second virtual machine belong, according to the subnet identifier; • forwarding, by the gateway, the packet to the second virtual machine in the second server according to the routing table; • receiving, by the service zone manager, the routing table from the gateway (step 301); • determining, by the service zone manager, a registration state of the first server, and when the first server is a registered server, sending, by the service zone manager, the routing table to the first server (step 303). • when a first virtual machine on the first server needs to send a packet to a second virtual machine on the second server, determining, by the first server, through searching, whether a routing table of a same tenant to which the first virtual machine and the second virtual machine belong exists on the first server (step 405), wherein the first virtual machine is located in a first service zone being managed by the first cloud management function and the second virtual machine is located in a second service zone being managed by the second cloud management function, and the packet comprises a subnet identifier of the first server; • when the routing table of the tenant does not exist on the first server, sending, by the first virtual machine on first server, the packet to the gateway (step 407); • receiving, by the gateway, the packet destined for the second virtual machine on the second server and sent by the first virtual machine on the first server; • acquiring, by the gateway, the routing table of the tenant, to which the first and second virtual machine belong, according to the subnet identifier; • forwarding, by the gateway, the packet to the second virtual machine in the second server according to the routing table; • receiving, by the service zone manager, the routing table from the gateway (step 301); • determining, by the service zone manager, a registration state of the first server, and when the first server is a registered server, sending, by the service zone manager, the routing table to the first server (step 303).