Abstract: According to the technology system and navigation principle of the microwave landing system (MLS) and to the electromagnetic similitude theory, the scale model of the environment of an airport equipped with the MLS is set up to simulate the real propagation situation of the navigation signal transmitted by the MLS by the propagation of the laser in the indoor scale model of the airport. In view of the dissimilitude between the real airport and the scale model, a modeling test method of two-scale scaling is put forward. The numerical simulation results of scattering of different kinds of scatters in the prototype system and the scale model system are compared with each other. The similitude of the electromagnetic scattering of the two systems is analyzed. The simulation results prove the feasibility of the scale model simulation system of MLS.