A lamp pumped CW Nd:YAG laser is presented in this paper. The main factors, which affect output power and beam quality of high power solidstate laser module, are theoretically analyzed. It is included that improving the laser efficiency to decrease the stable range of the diopter( increasing the thermal focus), to decrease the product of beam parameter, and improving the beam quality of output laser. Total electrooptics efficiency of lamp pumped YAG crystal as high as 4% is attained, and output power is 647W with beam parameter product 22mm·mrad.