Abstract: In view of problem that performance of power supply of portable electronic equipments influences stable running of the equipments, the paper discussed design points of power supply of portable electronic equipments. It introduced selection of battery type and indicated that selecting lithium battery as backup battery is ideal; it analyzed protection modes of safety barrier of power supply and indicated that protection modes of safety barrier with current limitation and cut-off can improve anti-interference ability of power supply effectively; in view of problem of ringing in Boost circuit, it gave solutions of optimizing key loop of Boost converter which can reduce power ripple effectively.