A solid state circuit breaker, including a solid state switch, an inductor connected with the solid state switch in series and a fault detection circuit. The solid state switch has a gate electrode, a source electrode and a drain electrode. The fault detection circuit is used for detecting health status of the solid state switch and identifying fault type of the solid state switch in a condition that a fault occurs on the solid state switch based on one or more of a measured voltage between the source electrode and the drain electrode of the solid state switch, a measured voltage of two terminals of the inductor, a reference voltage and a switching control signal provided to the gate electrode of the solid state switch. A motor driving system having the solid state circuit breaker is further disclosed.