In this paper,a laser guidance hardware in the loop simulation system is proposed,which consists of a software simulation subsystem,a hardware in the loop simulation subsystem,and a visual simulation subsystem.The software simulation subsystem establishes the kinematics and dynamics model of the guided aircraft and the motion model of the target based on Simulink,which can complete the digital simulation inner loop attitude control and outer loop guidance of the guided vehicle.The hardware in the loop simulation subsystem is controlled by an industrial computer to control the laser guidance unit and the target simulation unit respectively,to realize the laser guidance for guided aircraft guidance.An improved fitting algorithm based on Gaussian spot is applied to improve the detection accuracy of the four quadrant detector.Simulink communicates with LabView via UDP communication protocols.The three dimensional physical model of the guided aircraft and the target is built with AC3D,and the co simulation of the guided aircraft and target is achieved based on FlightGear,and the view simulation subsystem is constructed.Simulation experiments show that the system is not only capable of completing the study of the flight attitude control and guidance law of the guided vehicle,but also realizing the three dimensional visual display in real time.