Regional policies and support represent essential factors facilitating regional tourism development. The paper constructs a difference-in-differences (DID) model design to explore the impact of a regional revitalization policy, the policy on Several Opinions on Supporting the Revitalization and Development of Gannan and Other Former Central Soviet Areas, on tourism development in the relevant area. Treating this implementation as a quasi-natural experiment, we show that the policy significantly contributes to tourism development. We further identify the mechanism of the policy-tourism causal relationship through the mediation effect model. Results indicated that the regional revitalization policy fosters tourism development by promoting economic growth and transportation accessibility. Lastly, province-based heterogeneity analysis recognized a stronger policy effect in Guangdong and Fujian Provinces, which witnessed higher economic levels. Several implications were provided based on the empirical evidence.