The invention discloses an experiment method of a rail train intermediate coupler experiment. A coupler impact principle is firstly used for testing coupler performance. Through collision simulation,data collection, arrangement and analysis are performed on force bearing and deformation of a coupler in a collision process. Furthermore the collected data are compared with designing data of the coupler, thereby accurately verifying whether the coupler can function according to the design and whether a designing requirement can be satisfied. The experiment method of the rail train intermediate coupler experiment has advantages of convenient operation, accurate and reliable result, etc.