The invention relates to a DC protection method capable of adjusting a protection range. A monitoring circuit, a comparator, a CPU unit, a DAC module, a switching circuit, an input module and a display interface are included, wherein a front power supply is respectively connected with the switching circuit and the monitoring circuit, the monitoring circuit is connected with the comparator, the comparator is connected with the switching circuit, the input module is connected with an input end of the CPU unit, the display interface is connected with the CPU unit, the DAC module is connected withan output end of the CPU unit, and the DAC module is connected with the comparator. The protection range can be manually adjusted according to different requirements of different situations, when a current or voltage in the circuit exceeds the set protection range, the switch circuit turns off the output of the current. The method is advantaged in that the protection range can be adjusted according to different requirements, design of a new circuit is not needed, and safety is improved while convenience is provided.