Based on survey data from 1,085 leading agricultural enterprises in Guangdong Province from 2019 to 2022, this study empirically examines the mechanism through which political connections affect leading agricultural enterprises’ participation in rural industrial revitalization. The results indicate that political connections positively affect leading agricultural enterprises’ participation in rural industrial revitalization, with fiscal support serving as a partial mediator between the two. Moreover, both policy-sensing capability and market-sensing capability exert moderating effects at both stages of the pathway of “political connections—fiscal support—leading agricultural enterprises’ participation in rural industrial revitalization”. In the first stage, both capabilities strengthen the positive impact of political connections on fiscal support. In the second stage, they both amplify the positive impact of fiscal support on enterprises’ promotion of integration of the primary, secondary, and tertiary industries and provision of social services, while attenuating the positive impact of fiscal support on enterprises’ engagement in linking with and driving farmers, ensuring agricultural product supply, leading technological innovation, advancing green development, and building well-known brands.