LED is a cold light source, the operating junction temperature cannot exceed the limit, and a certain margin must be left when drawing. The depiction of the entire luminaire must consider the difficulties of many aspects, such as beautiful appearance, convenient installation, light distribution, heat dissipation, etc., and it is necessary to find a balance among many factors, so that all the luminaires are the best. There are not many experiences, and many depictions are constantly improved. Some LED lighting manufacturers use external power supply or outsourcing. The lighting painter does not know much about the power supply. The heat dissipation space for the LED is large, and the power supply space is small. Usually it is necessary to find a suitable power supply to match after drawing the lamp, which brings certain difficulty to the matching of the power supply. It is often encountered that because the internal space of the lamp is small or the internal temperature is high, and the cost control is low, it cannot be equipped with a suitable power supply. Some LED lamp manufacturers have the ability to develop power supplies. At the beginning of the evaluation of the lamps, the power supply can be processed simultaneously to solve the above problems. In the depiction, it is necessary to summarize and think about the heat dissipation of the LED and the power supply, and control the temperature rise of the lamp, so as to describe a better lamp.