This paper presents a real-time GPU-based visualization of dynamic terrain in excavator simulator, which is an interactive system for the purpose of training human operators and corresponding researches. Firstly, we establish the kinematic model of excavator, so as to trans-fer the bucket tip's reference trajectories to corresponding, required reference angle sequence for each joint and to control motion sequences of articulated hierarchies. Then, our method use GPU to create the DDHM and digging offset map, with which we can perform the terrain de-formation entirely in the GPU. In order to improve the visual quality, we also present a method of procedural texture for deformation terrain. Finally, the Real-Time Optimally Adapting Meshes (ROAM) algorithm is used to render the dynamic terrain effectively.