Target simulation is a technology that can save time and cost of weapon testing. When long- wave infrared laser was used to project light spot on the spherical screen for target simulation, a trailing of the laser spot in the moving path will be generated. Such trailing makes it difficult to keep the dot target in its original shape. So the trailing interferes with the accuracy of the target identification. The influences of laser power, laser spot movement speed and screen material on the trailing were investigated by theoretical analysis and a series of experiments. Firstly, the higher the laser power was, the more obvious the tailing phenomenon was under the same laser spot moving speed. Secondly, the slower the laser spot moving speed was, the more obvious the tailing phenomenon was under the same laser power conditions. Finally, different materials had great differences in the absorption capacity of 10.6 μm laser. The worse the heat dissipation was under the same laser power conditions, the more obvious the tailing phenomenon was. The results show that the trailing phenomenon of temperature rise can be effectively eliminate and reduced by adjusting the laser power in real time according to the moving speed of the laser spot and using suitable materials for the screen. And the tailing phenomenon is effectively eliminated and reduced.