A crusher for synthetic resins comprises: a cylindrical rotor; interlocking blocks which are installed on the outer periphery of the rotor; rotary blades which are in a polyhedron form which is manufactured using cutting blades having one corner of 46 degrees or higher and combines with the interlocking blocks as attachable; and fixed blades which are fixed and combined around the cutting tip rotary path when the rotor is rotated and pulverizes synthetic resin by interaction with the cutting tip. The synthetic resin crusher according to the present invention improves installation structure of the cutting tip and prevents a phenomenon that the cutting tip is stripped and enhances durability of the cutting tip by increasing angles of the cutting blades and enhances productivity by forming the crushed synthetic resin chip to be automatically moved.
