Caching method used for server cluster, cache server and cache system

The invention provides a caching method used for a server cluster, a cache server and a cache system. The caching method comprises receiving a connection request from a management server; determining whether to establish connection according to the connection request; establishing connection between application servers corresponding to the connection request if the determination result is yes; transmitting connection saturation information to the management server to enable the management server to select a new cache address if the determination result is no; and obtaining a data acquisition request from the application server in response to the connection between the application servers corresponding to the connection request. The caching method provided by the invention can improve the work efficiency of each server in the server cluster.