With the developing of multi-core techniques, concurrent processing and big-data operation are becoming more and more popular. Facing the complexity of program behavior and the large amount of input data, the cache system needs to explore more optimization opportunities. Improving the utizlization, efficiency and throughput of cache system is always the hotspot of architectural researches. This survey analyzes the inner details of cache techniques and concludes the important issues on multi-core cache optimization, like latency problem, capacity problem and sharing problem. Furthermore, this paper introduces some typical solutions for these issues, as well as the new techniques and new optimization aspects in recent researches. Finally, a description of possible developing directions is presented at the end of this survey.