Abstract: By the synchronization method of coupled chaotic systems based on nonlinear function,the synchronization of Chua's chaotic system is investigated.When the coupling factor k = 0.5,the stability of the synchronous state of coupled chaotic systems based on nonlinear function is proved by the stability criterion of linear systems,and its validity is examined by numerical simulation.Based on the Routh-Hurwitz's stability criterion,the lower limit of the nonlinear coupling strength ensuring the synchronization is determined,and it is k > 0.427.This synchronization method of coupled chaotic systems based on nonlinear function is extended to the all-to-all-coupling network.The stability of the network synchronous state is proved.On this basis,the all-to-all-coupling secure communication system is constructed via chaotic mask.Numerical simulation proves its feasibility.