Embodiments of the present invention provide a method, an apparatus, and a proxy server for selecting cache replacement policies to reduce manual participation and switch cache replacement policies automatically. The method includes: obtaining statistical data of multiple cache replacement policies that are running simultaneously; and switching, according to an event of policy decision for cache replacement policies and the statistical data, an active cache replacement policy to a cache replacement policy that complies with a policy decision requirement. The automatic switching of cache replacement policies lowers the technical requirements on administrators. In addition, in the operation process of a proxy cache, a cache replacement policy that is applicable to a current scenario and meets a performance expectation of a user can be selected automatically, so as to make the technical solution feature good adaptability. Compared with the existing solution in which only a cache replacement policy is used throughout, the technical solution of the present invention can improve the performance of the proxy cache.