Abstract: An analytic formula for the mean temperature along the axial direction of a rotating cylinder shell irradiated by high energy laser beams is presented. For the laser beam with Gaussian distribution of power density, it’s very difficult to give an analytic expression, hence a fitting formula is derived. The formula is determined by only one fitting coefficient with physical meaning, which is called distribution factor. The results obtained by using the analytic fitting formula and numerical calculation agree well with each other. As an application example, a formula for rupturing time of inner-pressured rotating cylinder irradiated by laser beams is presented, and the results agree well with that of numerical calculation.