Under a short-circuit fault in low-voltage DC microgrid, the Solid-State Circuit Breaker (SSCB) can isolate the faulted area quickly and effectively, while its own safety and reliability depends on the snubber circuit. For the design of the snubber, however, traditional method suited for snubber of converter device cannot be directly applied, because the snubber for circuit breaker puts more stress on its overvoltage suppression and rapid absorption of fault energy instead of snubber loss reduction. Therefore, this paper proposes a design method for SSCB snubber circuit with overvoltage suppression ability. The snubber mechanism of discharge-suppressing type RCD snubber circuit after protection action is analyzed. Three performance indicators are selected and a detailed procedure for parameter design is proposed, then suitable snubber parameters are calculated after selecting working condition. Experiments are conducted finally to verify the correctness of the above analysis results and effectiveness of the discharge-suppressing type RCD snubber circuit. This work is supported by Science and Technology Support Program of Hubei Province (No. 2015BAA109).