Based on the perspective of National Integrity System, this article discusses the fact that state audit is the important part of anti-corruption system, acting as the promoter, dominator, supervisor and assistant, which makes direct contributions and indirect contributions in preventing corruption, investigating corruption and punishing corruption in anti-corruption. The role, function of state audit in anti-corruption are affected by the corruption status and characteristic, anti-corruption strategy, state leader’s political will and state audit system. Considering these factors, state audit should strengthen the responsibility and awareness of dominator in corruption governance, takes part in anti-corruption by more direct contributions.