Abstract: Droplets’ two-dimensional dynamic simulation was performed by GPU based on CUDA C. The simulation algorithm was optimized considering hardware characteristics of GPU parallel computation. The same algorithm was carried out by CPU. The computing time of GPU was compared to that of CPU for the cases with single droplet diameter but different droplet numbers. The results show that the larger the number of water droplets is, the more obvious the GPU parallel acceleration effect is. In the case with large number of water droplets, about 60 times speedup is achieved. And the computing time of GPU for the case with a typical distribution of multiple droplet diameters obtains about 30 times speedup.