As an endogenous system of national governance, government audit plays an important role in the realization of the objective of national governance. Combining with the connotation of good governance and the realistic results of economic environment in China, this paper defines the objectives of national governance as basic objective and deep-seated objective. Based on public accountability theory and signaling theory, we analyze the governance function of government audit, explore the bottlenecks of government audit participating in national governance. Based on the analyzing result of signaling transmission game among government audit, government and the public, we make an attempt to provide the signaling transmission mechanism on government audit participating in national governance in order to enhance the efficiency of national governance.