Abstract: In order to solve the accuracy of the judgment of chaos detection system’s states and to cast off defaults of the intuitive phase judgment method,this paper adopts the Lyapunov exponent to quantitatively judge states of the Duffing chaos detection system.Based on the analysis method and the algorithm of the Lyapunov exponent,we carried out the system simulation and data analysis.The result certifies the feasibility of using Lyapunov exponent to judge the states of the Duffing chaotic detection s...