The invention discloses a tire smashing device. The device comprises a shell, a feeding port is formed in the upper part of the shell, a clamp is arranged above the feeding port, is connected with a third motor, and is connected with a rotating arm, the rotating arm is connected on the shell, a second motor is connected on the rotating arm, and is electrically connected with a button, and the button is located at the end parts of clamping jaws, and is used for controlling the second motor to stop the rotating arm from rotating; a plurality of smashing cylinders which are transversely arrangedside by side are rotationally connected in the shell, each smashing cylinder is in a circular truncated cone shape, the directions of the small-diameter ends on the adjacent smashing cylinders are opposite, criss-cross cutting edges are arranged on the outer walls of the smashing cylinders, and each smashing cylinder is hollow; and hollow supporting rods are arranged in the smashing cylinders, thetwo ends of the supporting rods are connected with the inner walls of the smashing cylinders, and impact pieces with the weak magnetism are arranged in the supporting rods. By adopting the technicalscheme, the service period of each smashing cylinder can be protected, the equipment investment cost can be reduced, a tire can also be fully smashed, and the working efficiency can be improved.