The institutional environment of the home country serves as a crucial foundation for supporting enterprises in “going global”. Against the backdrop of the underdeveloped establishment of a unified national market, and in response to the distortion in resource allocation caused by local governments’ investment attraction strategies, this paper focuses on the supportive role of competition policy for Chinese enterprises to participate in international market competition. Using the quasi-natural experiment provided by the implementation of the Fair Competition Review System in 2016, this paper empirically tests the impact and mechanism of competition policy on the “going global” of enterprises based on the samples of A-share listed companies from 2012 to 2022. The results show that by breaking the administrative monopoly, competition policy forces local governments to change the strategy of attracting investment, which not only has a significant positive impact on the scale level of enterprises “going global”, but also effectively improves the quality of enterprises “going global”. This conclusion still holds after a series of robustness tests. Mechanism analysis shows that competition policy can exert the “enabling effect” of business environment optimization, the “spillover effect” of foreign capital attraction, and the “synergistic effect” of industrial agglomeration, helping enterprises “go global”. Heterogeneity analysis shows that the promotion of competition policy on enterprises “going global” is more significant in the regions with strong government digital governance capacity and the industries with regional industrial agglomeration, and is affected by the degree of enterprise uncertainty perception and the level of regional technology adoption. This study provides empirical evidence for strengthening the rigid constraints of fair competition review and promoting high-level opening-up by deepening the institutional opening-up in the field of competition.