The fouling phenomenon of the insulation equipment outside the substation will affect the safety and reliable operation of the substation. Traditional cleaning methods have been unable to meet the requirements. In this paper, the continuous laser is applied to insulator cleaning and a finite element model is established for laser cleaning of porcelain insulator. Three factors influencing the effect of laser cleaning have been discussed, including the power density of pulse laser, the radius of the laser spot and the scanning velocity of laser. The simulation results show that the power density and radius of the laser spot are positively correlated with the highest temperature of the pollution surface, while the scanning velocity is negatively correlated with the pollution surface temperature. Furthermore, the variation tendency and the influence of the above three factors on the surface temperature are analyzed.