As the source of solar street lamp, LED light source is basically used. In the process of using, we often encounter the situation that LED is not bright, which is the dead light phenomenon of LED lamps. There are usually two reasons for causing dead lights. One is the leakage of LED, which results in the failure of the PN junction to cause partial dead lights. The whole lamp is not affected. The two is the internal connection of LED lamps, which leads to the disconnection of the leads, resulting in the LED no current passing through and resulting in dead lights, causing the whole lights to not work properly. Through the careful analysis of the technical personnel of our department and the reference of the relevant documents both at home and abroad, the following suggestions are made for the prevention of the dead light 1. Prevention of static electricity. Static electricity is a great devil for the LED lamp. Any part of the problem will cause damage to the LED, so that the performance of the LED or even failure. We know that the human body electrostatic (ESD) can reach about three thousand volts, enough LED chip breakdown, in LED packaging production line, grounding design must be scientific and standardized, general requirements for the grounding resistance of 4 ohms, some applications requiring high the grounding resistance even up to less than 2 ohms. Two, as far as possible the use of automatic welding equipment, if use manual welding must strictly control the welding temperature, this is because the welding by hand, if the use of ordinary iron, iron at a temperature of 300-400 DEG C, the temperature is too high will cause the welding dead lights, LED lead coefficient ratio at about 150 deg. C expansion coefficient is several times higher in expansion under high temperature, the internal wire solder joints because of excessive expansion and contraction of the welding point opened, causing death light phenomenon.