The STCW series laser power supplies are made for CW lamp-pumped Nd:YAG lasers. The main circuit of the power supply is based on power electronic module IGBT, adopts PWM technique to yield conversion efficiency more than 90%, and outputs constant current with high accuracy and low current ripple. Ignition circuits which produce a high voltage pulse consists of three steps: series high voltage unit for igniting the lamp, LC unit to relay the power, and low –voltage-constant-current to continue the lamp current. Automatic igniting is achieved with igniting-detecting circuit. The successful ratio of one-time ignition is more than 99%. The high voltage rises smoothly, and its magnitude can be adjusted to meet the dispersible characteristics of the krypton lamps, and to reduce the spattering of the electrode material at the same time, and further to reduce the damage to the krypton lamp caused by high voltage triggering.