The invention discloses a double-crushing-room structure and a crushing device and a working principle of the crushing device. A plurality of stationary knives are embedded on a left box piece and a right box piece, two baffle plates are arranged in a box body, a plurality of stationary knives are embedded on the baffle plates, a claw blade and a toothed blade sleeve a main shaft, the front end and the rear end of the main shaft are fixed in a front end tray and a rear end tray respectively, an induction wheel sleeves a part, exposed out of the front end tray, of the main shaft, an induction probe is arranged under the induction wheel, and a handle is also arranged on the front end tray. The crushing device has the crushing efficiency at least doubled the crushing efficiency of the crushing device with the common single crushing chamber, raw materials can be prevented from splashing during crushing when passing through a feeding hole due to a material stopping belt; the induction probe is arranged under the induction wheel, when the raw material is hard and cannot be broken to cause machine blockage, the induction probe feeds back the information, a motor rotates reversely, the raw material is recrushed by the claw blade, the operation is repeated until the raw material is broken and crushed; and the crushing room can be opened outwards by a hinge and the handle and is convenient to clean, and the working efficiency is greatly improved.