In order to study the damage effect of CCD detectors, the principle and method of mixture frequency laser by using double beams combination device was proposed. The double beams combination device by using the ZEMAX was emulated, and the far field light spot was collected in the meantime. The thermal mechanical physical model of CCD light shading Al film irradiated by mixture frequency laser is set up based on heat conduction and thermal elastic mechanics theories, the heat conduction differential equation and stress-balance equation are solved by the semi-analytical method, the temperature field and thermal stress field of light shading Al film are obtained. Through the numerical simulation, the damage effects of CCD by the laser source in different working modes were compared.