The invention discloses a pin-type plasticizing structure of a spiral propulsion injection molding device. The plasticizing structure comprises a front body, a screw head, a check ring, a check pad, a screw, a cylinder, a fixing device, and the like. According to existing injection molding device plasticizing structures, mixing rings are commonly used for carrying out preliminary mixing and stirring upon plasticizing raw materials, such that two or more raw materials can be uniformly mixed to achieve a color mixing effect, and certain plasticization effect can also be achieved. However, because the mixing ring is positioned between the screw and the cylinder, when the screw rotates under the driving of a motor, greater energy is needed for overcoming the friction forces between the screw, and the check ring, the check pad and the mixing ring. The invention provides a novel plasticizing structure, in which a pin is used for replacing the mixing ring, such that a purpose of friction force reducing is achieved.