Series robots are widely used in industrial production, so it is an important task to improve the accuracy of robots. In the series robot, the components are connected in series by rigid hinges, and the influence of hinge clearance on the motion accuracy of the robot cannot be ignored. As the influence of clearance on robot motion is nonlinear, it is difficult to obtain its inverse kinematics model by analytical method. The inverse kinematics model of the series robot with clearance was established by using the improved neural network of genetic algorithm, and the internal model control was constructed to realize the control of the series robot with clearance. The simulation results show that it has a certain control effect.