Abstract: The traditional image scaling algorithm in CPU based on bilinear interpolation has to confront with the problem of slow scaling. In this paper, GPU as a burgeoning high performance computing technique, implemented fast zooming on the GPU based on bilinear interpolation. In this algorithm, each pixel of the target image is allocated to each thread in GPU, and the interpolation efficiency is improved. The experimental results show that compared with the CPU single thread and multi thread, this algorithm significantly improved the interpolation speed of GPU, with the increase of the image resolution, and can achieve the effect of real-time image zooming.