The utility model discloses a digital control square wave phase shifter based on double frequency and double frequency. Square waves with the input duty ratio of 50% are subjected to differential rectification, and square wave signals are subjected to frequency multiplication; the differential pulse width is broadened to a certain width through the fixed pulse width broadening circuit; and integrating the fixed pulse width pulse wave to obtain a sawtooth wave, inputting the sawtooth wave into a comparator, controlling the output voltage of the DAC by a CPU to adjust the comparison level to realize phase shift, and performing frequency division on the output of the comparator to obtain a phase shift square wave with the duty ratio of 50%. The circuit is simple and easy to understand in principle, easy to realize in circuit structure and high in practical value.