As cache is the main energy- consuming component of a processor, how to improve its performance and reduce its power consumption has become the key of the study. In this paper, an adaptive rapid reconfigurable cache algorithm was proposed, by analyzing and comparing the characteristics of program segments and adopting the method of pre_reconfiguration, cache's capacity and associativity can be adjusted quickly when the phase changes. The result of the experiments shows that compared with the traditional fixed cache, the proposed algorithm can reduce power consumption by 40% and the performance loss is not more than 3%. Compared with Tourament cache, the algorithm has optimized both the performance and the power consumption of cache.