This paper uses the combined data of China’s industrial enterprise database and customs trade database from 2000 to 2013 to measure the domestic value-added rate of enterprises’exports. On this basis, it studies the impact of the development of bilateral diplomatic relations on the domestic value-added rate of Chinese enterprises’exports. The results show that the development of bilateral diplomatic relations will increase the domestic value-added rate of enterprises’ exports, and this result still holds after the robustness test such as variable substitution and replacement of regression methods. The mechanism test shows that the impact of the development of bilateral diplomatic relations on the domestic value-added rate of enterprises’exports is mainly achieved by reducing the relative prices of domestic and foreign intermediates and increasing the mark-up rate of enterprises. The heterogeneity analysis suggests that the development of bilateral diplomatic relations will significantly increase the domestic value-added rate of low-tech enterprises’exports, but it will inhibit the domestic value-added rate of high-tech enterprises’exports. Compared with the countries along the Belt and Road, the development of diplomatic relations has a greater effect on the domestic value-added rate of enterprises’exports in countries that are not along the Belt and Road. In addition, further analysis shows that the financial crisis, the imposition of tariffs and economic policy uncertainty will weaken the effect of the development of bilateral diplomatic relations on the domestic value-added rate of enterprises’ exports.