The invention discloses a device for detecting, filtering, and gathering microbes in the air. The device comprises a detection device, an air-suction device, and a gathering device; the detection device is communicated with the air-suction device through a connection member, the air suction device is composed of a sleeve and a fan, a first filtering screen is arranged in the sleeve and the joint between the sleeve and the fan, the detection device is composed of a U-shape pipe and a plug, one end of the U-shape pipe is connected to the connection member, the other end is connected to the plug, the joint between the U-shape pipe and the plug is provided with a scale, the detection device is communicated with the gathering device through a communication pipe, a valve is arranged on the communication pipe, the gathering device is composed of a gathering bottle and a vacuumizing pipe, a unidirectional valve is arranged on the vacuumizing pipe, and the opening of the gathering bottle is provided with a rubber sealing ring. The device has the advantages of simple structure, convenient operation, low investment cost, high detection precision, and obstruction resistant performance.