State audit has played an important role in local government debt supervision in recent years， but whether the actual effect has been achieved remains to be verified. Based on the local government debt and audit data of 30 provinces and municipalities in China （except Tibet） from 2010 to 2015， this paper empirically examines the impact of state audit on local government debt risk. It is found that the risk of local government debt is negatively correlated with the performance of state audit， and the better the performance of state audit， the lower the risk of local government debt. Further study finds that the lower the fiscal transparency，the more significant the role of state audit on the risk of local government debt. Higher fiscal transparency can reduce the high dependence of local government debt risk prevention on state audit.