The invention provides a bridge displacement extreme value response analysis method under moving load excitation, which comprises the following steps: firstly, carrying out Fourier transform on a moving load acting on a bridge, and carrying out Fourier transform on a bridge displacement response under the action of the moving load to respectively obtain a moving load spectrum and a bridge displacement response spectrum; and then establishing the relation between the moving load spectrum and the bridge vibration displacement response, the moving load speed causing the extreme value response ofthe bridge free vibration displacement can be determined, and the moving load speed causing the maximum displacement response of the bridge free vibration can be further determined. According to the invention, the bridge vibration displacement response spectrum obtained by the frequency domain can effectively reflect the free vibration of the bridge displacement response; and when the bridge has the maximum displacement response of free vibration, the moving speed of the moving load is only related to the bridge natural vibration frequency and the bridge span, and the speed corresponding to the extreme point in the moving load spectrum is matched with the speed of the bridge vibration displacement response extreme point obtained in the time domain.