In order to resolve safety issue of outsourcing data and verifiable delegation of computation,the theory of verifiable computation starts to draw public's attention recently.This paper illustrated how verifiable delegation of computation technique resolves above verifiability issues and provided formal definition of verifiable computation.This is the first time to summarize and induce current schemes from different classification methods,and illustrate key techniques and deficiency.Then this paper compared and analyzed these schemes from two aspects of function and performance.Finally,combined with the application hotspots,we forecasted tendency and development perspective in this research area from different application directions.