Research on real time dynamic water surface is a hotspot in the study of virtual reality with very broad application prospect. With the rapid development of calculating ability of GPU (Graphics Processing Unit) and the development of HLSL (High-Level Shader Language), the tasks such as vertex shader ,pixel shader, calculation of normal vector, dynamic texture mapping and calculation of water reflections and refractions can be done by GPU. In our research we studied the key factors affecting the effect of dynamic water surface and indicated that the writer presents some opinions which can generate more accurate reflections and refractions of water through adjusting light intensity and colorimchy by lighting and perturbing 2D texture mapping with normal mapping. A shader program in Virtools has been written and applied in virtual reality project. In the actual operation the effect is real and the rendering speed has greatly increased.