In order to study the influence of temperature on imaging quality of vehicle-mounted sight,the influence of temperature variation on structure parameters of the optical system was analyzed.Based on which,and with some wheeled artillery sight as the study object,the optical system model was established,and simulation analysis was made to the system model by setting different ambient temperatures.The root-mean-square value of diffused spots was used to represent the imaging quality of optical system,and the change law of imaging quality for this sight at different temperatures was obtained.Simulation results show that the imaging quality of this sight at low temperature is better than it at high temperature as a whole,with the best quality at about -20℃.This study lays a foundation for further evaluating the influence of temperature on the imaging performance of vehicle-mounted photoelectric system,and is of great reference value to the environmental adaptability design of new vehicle-mounted sight.