Abstract: To solve the problems of insufficient stability and response lag in the discrete design of traditional DC regulated power supplies and leakage protection systems, an integrated system solution is proposed to meet the strict requirements of modern electronic equipment for power supply stability and electrical safety. Taking the TMS320F2406 microcontroller as the core control unit, the hardware adopts a current-expanding scheme with multiple LM2940 chips connected in parallel to construct a 5 V DC regulated power supply. A leakage detection module is composed of the TLV272 differential sampling circuit and the LM393 voltage comparison circuit. Modular programming is used in software, integrating functions such as parameter setting, data acquisition, real-time power calculation and status display, so as to build a trinity architecture of "digital control-analog detection-intelligent interaction". Under a 5 Ω fixed load and within the input voltage range of 5.5～25 V, the output voltage of the system is stabilized at 5 V±0.05 V, with a voltage regulation rate of 0.23% and a load regulation rate of 0.42%. When the leakage current reaches 29.987 mA (with an absolute error of only 0.013 mA relative to the set value of 30 mA), the relay acts quickly to cut off the main circuit, and the output voltage drops to a safe range.