Aiming at the safety problem of robot force / position control application, a fast and practical robot collision detection algorithm based on a dynamic model is proposed. Firstly, design the robot force / position safety control program, establish a dynamics-based collision detection mathematical model. Then, based on the static LuGre friction model to identify and compensate the robot joint friction, design a simplified robot force / position control collision detection model. Finally, using a light industrial robotic arm as an experimental platform, the robot executes force / position control to collide with human to verify the algorithm. The experimental results show that the proposed method can detect abnormal collisions of more than 4 N·m between the connecting rods of the robot, and can effectively realize the safety control of the robot force / position, which has a certain engineering reference value.