Abstract: Direct pumping technique of micro-modularization diode side-pumped solid-state laser(DPL) was studied. The pump distribution of laser diode in gain medium was analyzed. The results show that the distribution of the gain relates to the parameter such as the waist radius of the emitter, the number of the bar around, the distance between pump sources and crystal surface, the radius of the crystal rod and the absorption coefficient of the crystal. Through adjusting the above pump parameters the pump distribution can be realized which has the character of strong center and weak edge. An experimental equipment of laser diode symmetrically side-pumped Nd:YAG laser was also designed, and the miniaturization of diode pumped solid state laser was achieved.