Dismounting device of cylinder-head valve seat

The utility model discloses a dismounting device of a cylinder-head valve seat, comprising a main body, wherein a screwed hole is arranged in the main body and is provided with a screw, at least two tightening blocks which are oppositely arranged are articulated on the main body, each tightening block comprises a supporting-leaning part and a tightening part, all the supporting-leaning parts lean against a free end of the screw, outer teeth corresponding to inner teeth of the cylinder-head valve seat are arranged on the outer surface of the tightening part, the dismounting device of the cylinder-head valve seat also comprises an axial force-applying mechanism which is used for driving the main body to move linearly. The dismounting device of the cylinder-head valve seat is convenient to operate.