Precise simulation of the temperature distribution throughout welding process is basic for stress analysis. In this paper, numerical simulations and multi-factor regression were used to investigate how the three process parameters, laser power, spot radius and spot offset, influence the temperature distribution in Beryllium (Be) cylindrical shells. The experiments are designed by the compound response surface method. Based on numerical results, regression model are gained as an expression about laser power, laser spot radius and laser spot offset. Then the effects of these three parameters on temperature distribution were obtained. The results could provide guidelines for welding process of Be cylindrical shells.