The invention provides a power supply system and method based on a numerical control power switch and an operation terminal. A power supply module is electrically connected with a power utilization module through a power supply control module. The power supply signal output module is respectively connected with the first end of the resistor R1 and the G pole of the MOS tube Q1; the S pole of the MOS tube Q1 is respectively connected with the second end of the resistor R1 and the output end of the power supply module; the D electrode of the MOS tube Q1 is connected with the input end of the power utilization module; the power supply signal output module is used for obtaining a power supply control signal and transmitting the power supply control signal to the G pole of the MOS tube Q1 to enable the MOS tube Q1 to be conducted, the power supply module and the power utilization module form a loop, and the power supply module supplies power to the power utilization module. The power supplycontrol module has the functions of an oscillator, high-gain error amplification, a latch, push-pull output and the like, and has the effects of self-protection, output turn-off, duty ratio limitation and voltage loop control under the condition that an external power supply fluctuates.