Engineering construction waste crushing device and method

The invention provides an engineering construction waste crushing device. The engineering construction waste crushing device comprises a crushing box used for recycling waste disintegrating slag, a rotating shaft is rotationally installed in the crushing box, a rotating cutting knife shaft is arranged at the bottom in the crushing box, a discharging hopper is arranged in the crushing box, and the cutting knife shaft is located under the discharging hopper; the rotating shaft is rotationally installed in the discharging hopper in a penetrating mode, the top of the discharging hopper is provided with an impact assembly used for conducting preliminary crushing on building waste, the waste is impacted and crushed firstly, then the waste is smashed through a cutting knife shaft at the bottom of the crushing box, the waste is crushed in different modes in a staged mode, and it is guaranteed that the waste is fully crushed; the invention further provides a crushing method based on the engineering construction waste