Based on the micro-survey data of 424 family farms in Hunan Province in 2022, this study employs the propensity score matching method to empirically examine the impact of joining cooperatives on the supply level of agricultural socialized service by family farms. The study indicates that joining cooperatives can significantly improve the supply level of agricultural socialized services by family farms; The impact of joining cooperatives varies for different types of agricultural socialized services; Enhancing the awareness of agricultural socialized services among family farmers serves as an i...