The invention discloses a wood dust collecting device and relates to the technical field of wood processing equipment. The wood dust collecting device comprises a box body, wherein an air inlet and anair outlet are formed in a front box panel and a rear box panel of the box body respectively, the air inlet of the box body is connected with a dust cover through a telescopic dust suction pipe, andan exhaust fan controlled by a motor is arranged at the air outlet of the box body; an isolation layer is arranged between the air inlet and the air outlet and located in the box body and divides thebox body into a dust collecting bin and an air outlet bin; an isolating plate with a groove and a filtering net are arranged on the isolation layer, one end of the filtering net is inserted into the groove of the isolation plate, the other end of the filtering net is fixedly connected to the inner wall of a first bin door at the bottom of the box body, and the first bin door can be taken out of the bottom of the box body. Compared with the prior art, the wood dust collecting device can solve the problem that wood dust produced during existing wood processing process cannot be cleaned up.