With the rapid development of new employment forms in China, labor outsourcing, as a flexible employment form, has released the institutional dividends of the labor market and brought scale growth to enterprises, but whether it can further achieve improvements in efficiency and fairness requires theoretical and empirical evidence. Based on the construction of a theoretical model, this paper uses data from Chinese listed companies from 2015 to 2023 to analyze the efficiency improvement and distribution reconstruction effects of the labor outsourcing model. The results show that: on the one hand, the introduction of labor outsourcing is conducive to the improvement of total factor productivity of enterprises, and its mechanism lies in the optimization and promotion of labor outsourcing model on management costs, labor productivity, and enterprise resilience; on the other hand, labor outsourcing can increase the labor income share, but at the same time it can trigger risk-taking and labor income differentiation between formal and informal employees, and lead to labor substitution for capital. Labor outsourcing has a more prominent effect on improving the efficiency of labor-intensive enterprises and private enterprises, and a more prominent effect on the distribution of capital-intensive enterprises and state-owned enterprises.