This paper presents a method based on vision for the calibration of surgery robot's DH parameters.The robot calibration model is built based on the robot model and the camera model.The error equation is built based on the position and posture error,and then is optimized by numerical method.This calibration method makes the absolute accuracy of robot raised to 0.6378 mm from8.5645 mm,with the advantages of simple operation and simple devices,which is convenient for surgeon environment.