The invention relates to a protection property testing device of a miniature circuit breaker. The device is characterized by comprising a monitor, a host, a keyboard, a mouse, a test control circuit, a test current generation circuit and a voltage and current conversion circuit, wherein the host is respectively connected with the monitor, the keyboard and the mouse to form a standard industrial personal computer, the host is sequentially connected with the test control circuit, the test control circuit, the test current generation circuit and the voltage and current conversion circuit, and the voltage and current conversion circuit is connected with the host of the industrial personal computer. The protection property testing device of the miniature circuit breaker has the advantages that the voltage and current of the miniature circuit breaker can be recorded in real time and at high speed (with sampling rate more than 4 microseconds), the recording collection start time is controlled by the industrial personal computer, and the collection finish time is controlled by touch head state.