A ray tracing algorithm based on GPU is designed and implemented to realize real-time ray tracing technology on personal PC. This paper introduces the principle of ray tracing, analyzes the characteristics of real-time ray tracing, and studies the construction of the most difficult space accelerating structure and the search problem of the real time ray tracing. The results show that the algorithm can get a very realistic graphics effect, providing people with depth information, and realize the three-dimensional effect in 2D images. It has been widely used in the fields of simulation, geometric modeling, advertising, film, television, command and control, and the visualization of scientific computing.