Digital potentiometer applied to direct-current working state

The invention relates to a digital potentiometer, and provides a digital potentiometer applied to a direct-current working state. The digital potentiometer comprises a digital logic unit, a variable resistor and a nonvolatile memory, wherein the digital logic unit further comprises a digital interface, a volatile memory and a position decoder; the digital interface is connected with the volatile memory; the volatile memory is connected with the position decoder; the position decoder is connected with the variable resistor; and the nonvolatile memory is connected with the digital interface and used for automatically storing the position of a sliding end of the variable resistor so as to simplify user operation. The two ends of the variable resistor are connected with direct-current voltages of which the voltage difference is more than a fixed numerical value, a high resistance end of the variable resistor is connected with a power wire of the digital logic unit, a low resistance end of the variable resistor is