Method and device for expanding server cluster system and server cluster system

The invention discloses a method and a device for expanding a server cluster system and the server cluster system. The method comprises the steps that a load balancing server receives a first access request from a client; the load balancing server calculates a first hash value; the load balancing server determines an original cache server corresponding to the first hash value; the load balancing server calculates a second hash value; the load balancing server determines a cache server corresponding to the second hash value; the load balancing server receives contents, corresponding to the first access request, in the original cache server corresponding to the first hash value through the additional cache server corresponding to the second hash value; the load balancing server sends the received contents to a client. According to the method, the additional cache server acquires service contents from the original cache server instead of a source station, so that the effect of increasing the hit rate of the cache server and reducing the pressure on the source station are achieved.