The chaos characteristics of automobile suspension under quasi-impulse excitation were studied by numerical simulation and experiment. The 2D model of automobile suspension was built, which was subjected to the quasi-impulse excitation. The time history curve, power spectrum, phase trace and maximum Lyapunov exponent were given out by numerical simulation. It was confirmed that the automobile suspension vibration was chaotic. The vibration acceleration curve of automobile suspension was obtained by triangle wood experiment. The characteristics curves of suspension vibration were calculated and analyzed by using Matlab, and power spectrum and phase trace were obtained. And then the maximum Lyapunov exponent was calculated. The chaos characteristics of automobile suspension vibration were verified.