During the large visual angle IR image distortion rectification process there are some difficulties, first pick-up rectifying points is hard, second measuring and rectifying distortion are wasting time, third rectifying screen is difficult to make and it costs much. In order to overcome those disadvantages an IR imaging distortion rectification method, which using asterisk rectifying screen, is proposed. This method takes the image of a special made asterisk rectifying screen at first, then using SIFT operator to detect the real imaging positions of rectifying points in the image. Based on the real positions mean slope is used to compute theoretical imaging positions of those rectifying points. After that least square arithmetic is adopted to calculate the distortion parameters. The experiment result has shown that: the proposed method has the advantages of high precision, low cost, simple process and universal applicability.