Abstract: Aiming at the problems that the DC circuit breaker in the DC side combiner box of the current photovoltaic system has severe arcing, which shortens the life of the circuit breaker and reduces the reliability of the system, this paper proposed a new arc suppression topology based on capacitor buffering. This topology mainly used a IGBT device and a parallel capacitor to form a pre-discharge circuit. At the instant when the circuit breaker was opened, the IGBT was turned on by detecting the voltage between the circuit breaker breaks, and the capacitor discharged the load to increase the voltage across the load and reduced the voltage across the circuit breaker. The voltage across the device's fracture was lower than the arc voltage. This article described in detail the topology, working principle and control strategy of the proposed scheme. And through the establishment of Simulink simulation and test prototype to verify, the results show that this scheme can significantly reduce the breaking arcing time of photovoltaic circuit breakers. The topology has a significant effect on eliminating fire hazards in the first-level combiner box, improving system reliability.