LED is characteristic sensitive semiconductor device, and has negative temperature characteristic, so it needs to be stable working state and protection in the application process, thus giving rise to the concept of driving. LED components on LED drive power requirements are almost harsh, LED unlike ordinary incandescent bulbs, can be directly connected to 220V AC power supply. Leds are low voltage drives of about 3 volts, and have to be designed with complex switching circuits, different LED lights for different purposes, and equipped with different power adapters. In the international market, foreign customers have very high requirements on efficiency conversion, effective power, constant current precision, power life and electromagnetic compatibility of LED drive power supply. To design a good power supply, these factors must be considered comprehensively, because the power supply in the whole lamp is as important as the heart of a person.