Installation errors in the process of erecting the seeker and target simulator are inevitable in infrared imaging guidance semi-physical simulation experiments. In order to improve the guidance precision and simulation credibility of the test, a static mathematical model and correction method for the installation error are established by analyzing the causes of the error. Analysis of the motion trajectory of the target simulator cell center allows classification of the installation error, following which the mathematical model of the installation error is derived. OpenCV is used to process the seeker guidance image. Next, we obtain the coordinate information needed to solve the error model, and finally, we modify the ballistic guidance model. The simulation verification is conducted to quantitatively analyze the influence of error correction on the miss distance, which has a certain optimization effect on guidance attack.