Time delay has a great impact on the performance of the control system, and even leads to the unexpected instability of the feedback control system. Aiming at the adverse effect of time delay on the control effect and stability of active suspension system, this paper proposes to suppress the complex dynamic behavior of vehicle by applying time-delay displacement feedback. In this paper, the time-delay feedback control characteristics of the system are studied by combining theory with experiment. Firstly, the dynamic equation of suspension system with time-delay is established, the system stability is analyzed by frequency domain scanning method, the simulation model is established, and the superiority of time-delay feedback control under external excitation is verified by comparing harmonic excitation with passive control and backstepping control. Finally, the 1/4 model bench test of the active suspension system is carried out, and the comparison between the simulation results and the test results under the same working conditions shows that the two have good consistency. The results show that the research is credible, and the research results can provide reference for the actual design and application of active/semi-active vehicle suspension controllers.