This paper focuses on the influence of joint clearance on the satellite dashes when the space environment alternates between cool and hot. Since the whole truss structure is complex and has many kinds of clearance,this paper only studied the nonlinear dynamical behavior of synchronous straight bevel gears which have clearance after the synchronous straight bevel gears is locked. The first model is Hertz contact force model; the second one is coefficient of restitution model; the last one is nonlinear springdamping model. Then the physical model was simplified, the dynamic one was obtained, and the dynamic equation with the nonlinear springdamping model was established. Due to the existence of segmentation in the dynamic equations, direct solve analytically is difficult, so this paper used numerical simulation method to analyze the model. From the analysis, it is obtained that the system of synchronous straight bevel gears with clearance will appear complex nonlinear phenomena such as Singleperiodic, perioddoubling bifurcation and chaotic responses.