Advanced international soft switch technology is adopted with passive PFC added.That increases the adaptability to the impact from electricity grid and reduces the output pollution . A new isolation technique is adopted to the circuit design.-input/output,input/control, output/control are all aloofed from eath other, which is of high anti-jamming and stable. input voltage range:380V±20% we adopt dummy load and flow equalization technique to solve the problem of flow equalization during part load time. Then PWM wil control the circuit and work in normal situation. more suitable for the electricity operation,power supply system. multilevel protecting design is adopted, it can protect against overvoltage, high temperature, overcurrent, and can resume normal working condition automatically.900V voltage withstand MOS tube is adopted to increase the ability of withstand overload and impact.Hight working efficiency,small ripple,excellent input feature and high conversion efficiency are also its obvious characteristics.