A type of new internal wave generation method——in-box heaving method is put forward. Through the application of finite volume method(FVM)of FLUENT software，and by using the k–ε two equation turbulence model to close the RANS equation as the governing equation，a two-dimensional numerical internal wave flume is established. By numerical simulation in imitation of physical wave generation method，the result shows that the internal wave profile obtained by the in-box heaving wave generation method conforms to the theoretical value well. Compared to double-piston wave generation method and flat slapping piston wave generation method，this wave generation method is easier to control，and the disturbance on the surface caused by the motion of wave generation is smaller and more stable. In addition，the wave generation system has a strong adaptability to the depth variation and position change of stratified interface in the box，which will not cause mixing of stratified water bodies.
