Mainly designed for simulating the fluid motion, Smooth Particle Hydrodynamics (SPH) SPH has been widely applied to many fields, such as aerospace aircraft design and ship design. First, this paper presents an implementation of serial SPH method algorithm using the reflection method as the boundary condition. This paper describes entire process of SPH and gives detailed descriptions of some important procedures. Second, this paper realizes the corresponding parallel algorithm of SPH, which includes neighbor particle searching and building, physical attributes computation and other main SPH method procedures. Third, details of mapping different parts of the SPH serial algorithm to parallel algorithm on GPU with CUDA C as parallel programming language are also shown in this paper. Taking advantage of powerful computation ability of GPU, the experiment approximately achieves a 8X speedup that shows the high efficiency of GPU-based programming. The parallel algorithm not only achieves a high performance, but also promises a reliability result with a small error rate as the experiment result shows.