The establishment of pilot free trade zones has significant economic significance for the economic growth of the regions they belong to. Taking the Sichuan-Chongqing region as an example, a counterfactual analysis of the economic effects of the pilot free trade zone was conducted using synthetic controls based on GDP quarterly growth rates, import and export volumes, and fixed asset investment data from the first quarter of 2008 to the second quarter of 2019 for provincial-level samples nationwide. The results show that the establishment of the pilot free trade zone has promoted economic growth in the Sichuan-Chongqing region, but this impact is heterogeneous. For Sichuan, the impact of trade-driven growth on economic growth is more significant than investment -driven growth; for Chongqing, investment-driven growth outweighs trade -driven growth, and the economic effects of the establishment of the pilot free trade zone have a certain lag.