Chassis of engineering vehicle and engineering vehicle

The chassis of the engineering vehicle comprises a vehicle frame and a cab floor, the vehicle frame comprises a first end and a second end, the height of the first end is smaller than that of the second end, the cab floor is arranged above the first end, the cab floor comprises a first-stage floor and a second-stage floor, and the second-stage floor is arranged above the first-stage floor. One end of the first-stage floor is connected with one end of the second-stage floor to form a step structure, the first-stage floor is close to the head of the engineering vehicle, and the first-stage floor is lower than the second-stage floor. The height of the cab can be reduced by designing the height of the first end of the frame to be smaller than that of the second end. And meanwhile, the first-stage floor and the second-stage floor of the cab floor are arranged to be of a stepped structure, and the first-stage floor is lower than the second-stage floor, so that the height of the cab can be reduced. The cab floor is