Infrared imaging guidance has been widely used in various countries due to the high sensitivity, spatial resolution and immunity to electromagnetic interference and so on. However, in the process of imaging guidance, image motion blur is easy to be caused for the relatively rapid movement between the projectile and target, which makes lateral movement and target size relatively change between the target and the imaging system and takes impact to the subsequent target recognition and tracking process. According to the images captured by imaging guidance system, at the condition of unknown motion parameters, point spread function (PSF) estimation algorithm is adopted. The motion direction and scale parameter of the function are determined by Roberts edge detection operator and auto-correlation algorithm. Based on this, the image is restored by constrained least squares filter algorithm. Simulation results show that the algorithm can better restore the motion blurred image and lay the foundation for infrared imaging guidance target recognition and tracking.