In order to study atomization effects of the cross-flow injector and the influence on engine thrust，a series of cold-flow tests were performed using impinging injector

reverse injector and horizontal injector. The Sauter mean diameter of droplet in spray field at the exit of engine nozzle and thrust characteristics of engine were studied at different test cases. The test results indicate that with the increase of pressure ratio

the droplet diameter decreases;the injection case of the minimal droplet diameter is the throat and expanding section injection when the pressure ratio is given

and the injector of the best atomization quality is the impinging injector; meanwhile

the ability to control the throat and thrust ratio for three kinds of injectors increases with the increasing mass flow ratio under the throat and expanding section injection.