With continuous development of the security industry and people′s growing demands for cameras, it was urgent to have the panoramic image with a larger field of view. As a result, kinds of splicing algorithms and splicing applications have come into being. Although the existing software algorithms have been able to achieve good results, but the problems of supplement light distribution in image splicing are still outstanding. Considering the situations above, the problems of inconsistency of illumination or light intensity in Light Emitting Diode(LED) were studied. The design idea of the Total Internal Reflection(TIR) lens was used for the secondary light distribution design, which made the illumination or light intensity of the light spot from LED uniform after splicing, and the simulation was done at the same time. The simulation results show that it could avoid too bright or too dim trace after the light spot splicing, and the splicing effect would be better. It could meet the requirement of the camera working around the clock.