power management system design and implementation scheme. This system with the STM32 MCU as the core, by TI company LM5117 and CSD18532KCSMOS step-down controller as the core device, by filtering module, voltage regulator module, AD module, voltage feedback control module, display module. Using LM5117 DC - DC function and feedback module, the system not only implements the function of constant pressure constant current power system requirement, moreover also has the function of over-current protection and load identification ability; By inhibiting the production of power supply ripple, satisfy the control system of low noise ripple voltage requirements, the other system anti-interference design.