Taking the prevalence of the global green development concept and China's green credit development practice as the background, this paper constructs a theoretical model analysis framework with the incentive policy of green credit as the entry point. First, the impact effect of green credit incentive policy is examined using the BVAR model. The results show that the green credit incentive policy suppresses the output level in the short run through the financing constraint channel, but has a positive contribution to output in the long run due to the adjustment of the production structure and the dynamic adjustment of green investment and R&D. Next, the paper constructs a DSGE model embedded with green credit fiscal and tax incentive policies, which explains the impact mechanisms and comparative effects of fiscal and financial policies driving green credit. The model shows that the re-guarantee policy is the most effective and consensual green credit incentive policy. In terms of the policy combination, the combination of the re-guarantee policy and the income tax policy is the current optimal policy pairing, and its policy is able to produce an amplification effect through the balance sheet channels of commercial banks and enterprises at the same time. In addition, a certain intensity of the above policy combination not only can effectively increase the scale of green credit, but also does not produce significant negative shocks to output and inflation. In summary, the findings of this paper provide a useful reference for the formulation and implementation of green credit incentive policies.