Abstract: This paper constructs a classic model of capital structure， and improves the model of capital structure adjustment based on the panel data of listed companies in Liaoning Province between 2006-2017. The systematic GMM estimation method is used to carry out regression estimation on the model， verify the dynamic optimization mechanism of the capital structure of the financial policy， and simultaneously analyze the adjustment speed and adjustment form of the capital structure. The results show that the central financial policy， local fiscal policy， taxation policy and monetary policy have different dynamic optimization mechanisms for capital structure; fiscal policy and monetary policy have an interactive effect on the dynamic optimization of capital structure; compared with a single fiscal policy， the interaction between fiscal policy and monetary policy has a more significant effect on the dynamic optimization of capital structure.

Key words: fiscal policy, capital structure, taxation policy, monetary policy