Abstract: Compared with traditional mechanical circuit breakers, solid-state circuit breaker (SSCB) has been widely noticed in the DC power grid for its fast-breaking speed and non-arcing advantages. However, solid-state circuit breakers are based on semiconductor switching devices, which require additional control and drive circuits in addition to the power circuit. The operation of this part of the circuit requires an external power supply, which increases the complexity of the system, especially, when the grid itself fails, the power supply may also be unstable, reducing the reliability of solid-state circuit breakers. To this end, a PMOS-based self-powered DC solid-state circuit breaker is proposed in this paper, and the feasibility and effectiveness of this solid-state circuit breaker are demonstrated by simulation and physical prototype, respectively. The experimental results show that the proposed solid-state circuit breaker is fully turned on during normal conduction, which does not affect the line voltage during normal operation; in case of short-circuit faults in the DC system, the short-circuit current coupling energy is used to enable the reliable turnon and turnoff of PMOS without additional power supply, which improves the stability and reliability of the system and can be applied to DC microgrids or small energy storage systems. It has good application prospects.