Abstract: To study the multi-path effect of airport approaching landing system, according to the theory of electromagnetic system in scale model, a controllable laser transmitting equipment is used to simulate the function of the angle navigation antenna of airport approaching landing system based on the feature of the laser beam, which emits well directional laser scanning signal. The feasibility of this method were analyzed in wave similarity, reflex point coordinates similarity, signal arrival time similarity in time axis, model of laser obstacles, scattering characteristics, and phase accuracy similarity. Experimental results show that the laser beam can simulate the multipath effect of real airport in scaled environment, which provides a new way for studying the multipath effect of landing navigation system.