Based on the view of strategic human resource management, and taking human resource system flexibility as mediating variable, a theoretical model of the relationship between entrepreneurial orientation and firm performance is established, and entrepreneurial orientation is divided into two dimensions, one is innovativeness and proactiveness, and the other is risktaking. An empirical analysis is carried out by using 381 data from the manufacturing enterprises in the Pearl River Delta, the results indicate that both innovativeness and proactiveness and risk taking have significant positive effect on firm performance; human resource system flexibility plays a partial mediating effect on the relationship between innovativeness and proactiveness and firm performance, but has no mediating effect on the relationship between risk taking and firm performance.