A power output voltage regulation circuit comprises a single chip microcomputer, a digital keyboard, an electric quantity detection chip, a signal processor and a voltage feedback circuit. The digital keyboard and the electric quantity detection chip are connected to the single chip microcomputer, the signal processor is connected to an output end of an active low-pass filter, the voltage feedback circuit is connected to an output end of the signal processor, an output end of the voltage feedback circuit is connected to an input end of the electric quantity detection chip, and an output end of the electric quantity detection chip is connected to the single chip microcomputer. The digital keyboard is used for regulating the set value of output voltage and inputting the set value to the single chip microcomputer, the single chip microcomputer outputs a duty ratio controlled square-wave signal which is converted into a reference value of the power output voltage by the active low-pass filter, and the voltage is outputted by the signal processor. If practical output voltage deviates from the set value inputted by the digital keyboard, the electric quantity detection chip feeds back the practical output voltage to the single chip microcomputer, the single chip microcomputer controls and regulates the duty ratio of the square-wave signal, and finally, the output voltage is consistent with set voltage.