In the overall design of the LED table lamp scheme, it is necessary to consider the transmission and radiation of EMI. The key to the transmission and radiation of EMI is the power converter. Therefore, it is necessary to select the adapter that can pass EMI, even CE and UL to match, so that the LED table lamp can be exported to the European, American and Japanese markets. Because the driving IC of constant current source power board is DC / DC switching device, the switching frequency will produce radiation when it works, so it can effectively reduce the radiation when it is built in the metal shell of the lamp base. The magnetic circuit shield in the metal base should be considered in the mechanical structure design.