The invention discloses a dust removal device capable of deashing through reverse blowing. The device includes a connecting pipe, a first by-pass pipe and a second by-pass pipe; the rear end of the connecting pipe is communicated with an air exhaust fan, the front end of the connecting pipe is communicated with a boiler through a smoke exhaust pipe, and the connecting pipe is provided with a firststop valve, a bag-type dust remover and a second stop valve sequentially from front to rear; the front and rear ends of the first by-pass pipe are both communicated with the connecting pipe, the front end of the first by-pass pipe is connected to the front end of the first stop valve, the rear end of the first by-pass pipe is connected between the second stop valve and the bag-type dust remover,and a third stop valve is arranged on the first by-pass pipe; the front and rear ends of the second by-pass pipe are both communicated with the connecting pipe, the rear end of the second by-pass pipeis connected to the rear end of the second stop valve, the front end of the second by-pass pipe is connected between the first stop valve and the bag-type dust remover, and a fourth stop valve is arranged on the second by-pass pipe. According to the dust removal device capable of deashing through reverse blowing, a cloth bag does not need to be disassembled, and deashing can be conducted throughreverse blowing.