Based on the Eaton and Kortum model, an analytical framework for the export effect of 5G patent standardization is constructed, and data from the European Telecommunications Standards Institute for the period 2002~2020 are used to analyze the impact and mechanisms of 5G patent standardization on China’s exports of ICT products to countries along the Belt and Road. The results show that 5G patent standardization significantly promotes China's exports of ICT products to these countries, with the export effect exhibiting an inverted U-shaped pattern. Mechanism testing indicates that trade competitiveness, national productivity, and participation in the GVC are important channels. The paper also finds that as the export scale expands, the corresponding export effect shows increased volatility. This research provides important policy insights for advancing the Belt and Road economic and trade cooperation and achieving high-quality development through standards.