The performance of the power supply is extremely important in the access control system. The selection of a dedicated power supply for the access control controller directly affects the safety and stability of the access control system. Compared to other power sources, the dedicated power supply for the access control controller has many special requirements. Although it also provides power, as it controls the electric lock, which is controlled through an inductance coil. When the electric lock is activated, there will be an instantaneous high current, and when the electric lock current ends, there will be a reverse voltage, This requires the power supply to be able to withstand frequent fluctuations in load. At the same time, because access control belongs to radio frequency identification, it requires the power supply to have small noise clutter and radiation, especially high-frequency noise interference, which can affect the card reading distance or cause equipment crashes or even burn down. Therefore, in the design of the dedicated power supply for the access control controller, it is necessary to fully consider various parameters such as stable waveform, no high-frequency noise, long-term continuous power supply, and the ability to withstand frequent load changes.