Abstract: On the basis of the Lamberts cosine law, the light intensity of a point on the receiving screen behind the diffuse transmission glass screen was theoretically deduced. Combining the application of the diffuse transmission glass screen in the power monitor, the influence of both single-layer glass and multi-layer glasses on the intensity distribution of the incident laser was summarized through numerical simulation. The numerical results show that when the ratio of the radius of the incident laser to the distance from the diffuse transmission screen to the receiving screen is no more than 0.3, the intensity distribution and the caliber of the incident laser couldnt influence the normalized light intensity distribution on the receiving screen. And the normalized light intensity distribution on the receiving screen mainly depends on the distance, which indicates that the arrangement of the glasses or the number of the layers almost have nothing to do with the distribution. This conclusion was proved by the experiment.