This paper presents HUBOT - a modeling and simulation platform specialized for multi-link robots. We use PhysX as the dynamics solver so that we can manipulate various physics parameters of the robot directly. Visualization is also supported based on OpenGL rendering environment. HUBOT solves kinematics and dynamics among the robot and the environment, sensor data simulation is also implemented to help evaluate robot status and test control algorithms. A biped walking simulation of a humanoid robot is presented as a demonstration of our simulation platform.