According to the actual investment and return situation, we here propose a generalized public goods game (PGG) model combining with the Nash bargaining. The effects of the segmental synergy factor and investment threshold on the evolution of individuals’ behavior are analyzed. The Nash equilibrium and Pareto optimality related to the PGG are theoretically calculated firstly, and then the influences of different factors on individuals’ strategy choose, the difference of individuals’ strategy and individuals’ gain are explored according to the numerical simulation. Results show that with the increase of investment threshold T, the difference of individuals’ strategy and individuals’ investment increase first and then rapidly decrease to 0. Therefore, once when the investment threshold T is larger than a certain value of Tc, all individuals will adopt the free-ride strategy. And there exists an optimal T that can maximize the average individuals’ investment. With the increase of the game round, individuals’ investment strategies tend to be stable, and the average investment of individuals in a heterogeneous network is greater than that in a homogeneous network. Our work tries to provide a deeper insight to network reciprocity.