Analysis of the Impact of China’s Regional Prevention and Control on the Transmission of Swine Diseases

China is the largest pork producer and consumer in the world, and the prevention and control of swine diseases are crucial for ensuring the sustainable and healthy development of the industry. Since 2019, China has initiated pilot programs for a regional prevention and control (RPC) policy targeting major animal diseases, aiming to effectively control African swine fever (ASF) and other significant swine diseases, while promoting high‐quality development of the pig industry. This study uses provincial panel data from China spanning 2017–2021, treating the implementation of RPC as a quasinatural experiment, and employs a difference‐in‐differences (DID) approach to empirically examine the policy’s impact on swine disease spread and its underlying mechanisms. The results indicate that first, RPC significantly reduces swine disease transmission, with provinces implementing the policy showing an average decrease of approximately 69.4% in swine disease levels compared to provinces that did not adopt the policy. Second, the mechanism analysis demonstrates that domestic swine trade partially mediates the policy’s effects; by restricting long‐distance interprovincial transport, the policy reduces regional swine trade volumes, thereby effectively curbing disease transmission. Swine farming scale and local slaughtering capacity did not show significant mediating effects, indicating that the policy’s effectiveness primarily depends on controlling the distribution channels rather than directly intervening in production processes. This study provides quantitative evidence on the effectiveness of RPC and offers insights for optimizing and improving future animal disease control policies.