A non-explosive underwater shock loading device exhibits many advantages as a new labscale research method of underwater explosion, including high reliability, low cost.This method has an important role on further research on underwater explosion.To generate impulsive loading similar to blast, the exponentially decaying underwater pressure was produced by a flyer plate struck a piston at one end of the water tank.The shock wave strength and decay constant in a certain working condition were determined.The reliability of the non-explosive underwater explosion shock loading device was investigated by experiment and numerical simulation.The results indicate that the device can effectively simulate underwater explosive shock wave.