The proportional guidance is often used in the terminal guidance section of surface-to-air missile,while the platform self-defense jammer is often used to defend surface-to-air missile.This paper discusses the control characteristics of proportional guidance for surface-to-air missile and the photoelectric interference environment.A new simplified calculation method for the flight trajectory of the missile in the terminal guidance section and a mathematical model for the miss distance of the missile after effective photoelectric interference are presented.Based on this,the hit probability of the missile under the interference condition is calculated and analyzed.This paper focuses on the boundary conditions when the missile cannot hit the target,that is,the corresponding missile attitude,range,and flight control parameters when the photoelectric interference is effective,and discusses the missile hit probability under photoelectric interference and the boundary conditions when the missile cannot hit the target.The study can be used to quantitatively evaluate the combat effectiveness of the platform self-defense interference equipment and evaluate the anti-interference performance of the missile seeker.