The invention discloses a respirator detector. The respirator detector comprises a to-be-tested respirator air bottle, a high-pressure sensor, a first cut-off valve, to-be-tested respirator pressure reduction valve, a medium-pressure sensor, a second cut-off valve, a to-be-tested respirator adjusting device, an artificial lung and a low-pressure sensor wherein one end of the high-pressure sensor is connected with the to-be-tested respirator air bottle, the other end is connected with a signal receiving end, one end of the first cut-off valve is connected with the to-be-tested respirator air bottle, the to-be-tested respirator pressure reduction valve is connected with the first cut-off valve, one end of the medium-pressure sensor is connected with the respirator pressure reduction valve, the other end is connected with a signal receiving end, the second cut-off valve is connected with the to-be-tested respirator pressure reduction valve, the to-be-tested respirator adjusting device isconnected with the second cut-off valve, the artificial lung is connected with the respirator adjusting device, one end of the low-pressure sensor is connected with the artificial lung, and the otherend is connected with a signal receiving end. The invention further provides a detecting method of the respirator detector, and the airtightness of a whole device, the outlet pressure of the respirator pressure reduction valve, the respiration resistance of a respirator adjusting device and flow rate detection can be detected in one attempt.