Abstract: The paper introduced design of an overall scheme and main circuit of high-precision digital controlled DC power supply. The power supply is based on switch regulator chip LM2596 and digital signal controller dsPIC30F4013, which combines high-efficiency of DC voltage-stabilized power and capabilities of high-precision data acquisition and processing of embedded system, and uses digital potentiomete MAX5478 to achieve adjustment of output voltage. The power supply has functions of output current protection, real-time display of voltage and current, matrix keyboard interactive feature. The test results showed that the power supply has advantages of stable output performance, strong load capacity and has practical value.