The invention discloses a rendering method and system of bone animation. The method comprises the steps that animation frames of the bone animation to be rendered are obtained, whether bone gesture matrix data of the animation frames exist in a cache mode is judged; if yes, the cached bone gesture matrix data are transmitted to a GPU, the bone animation corresponding to the animation frames is rendered; otherwise, the bone gesture matrix data of the animation frames are computed through a CPU, when the cache condition is met, the computed bone gesture matrix data and the animation frames are cached correspondingly; and the computed bone gesture matrix data are transmitted to the GPU, and the bone animation corresponding to the animation frames is rendered. According to the method and system, when the bone gesture matrix data with the animation frames to be rendered are cached, the cached bone gesture matrix data are transmitted to the GPU, the bone animation corresponding to the animation frames is rendered, CPU resources do not need to be consumed, and the rendering performance of a 3D engine can be improved.