The invention discloses a coupling-type environmental purification device and an application method thereof. The coupling-type environmental purification device comprises a purification device body, agas detector, a microprocessor, and a signal transmitter, and the gas detector is installed on the purification device body; the microprocessor is connected with the gas detector, the signal transmitter, and the purification device body in a data mode; the signal transmitter is used for transmitting data; and the purification device body comprises a purification module and the purification modulerealizes purification operation and self-cleaning operation of the purification device body. According to the coupling-type environmental purification device and the application method thereof, modular and detachable design is adopted, the detachable connection of a purification unit and a module main body is achieved through a connecting assembly, and convenient carrying and transportation can be achieved; according to specific using environments, assembled schemes of the purification module can be pointedly provided, and all levels of purification units can be freely combined and arranged;and at the same time, the purification unit is conveniently and rapidly changed, and filtering effect is not affected.