The invention relates to a novel injection oil cylinder apparatus of an injection molding machine. The apparatus comprises a rubber injection head plate, an injection piston rod, an injection piston end cover, an injection seat, an injection piston, an injection oil cylinder, injection pull rods, an injection oil cylinder bottom, injection oil cylinder pull rods, an injection oil cylinder cover and a material storage cylinder body. The apparatus is characterized in that the material storage cylinder body is fixed to the rubber injection head plate through a hole, the injection oil cylinder cover is fixed to one end of the injection oil cylinder body and is fixed to the injection seat through the injection oil cylinder pull rods, the other end of the injection oil cylinder body is fixed to the injection oil cylinder bottom, the rubber injection head plate and the injection oily cylinder bottom are respectively fixed to two ends of four injection pull rods, the injection piston moves between the injection oil cylinder cover and the injection oil cylinder bottom, one end of the injection piston end cover is fixed to the injection piston, the other end is fixed to the injection piston rod, and the injection piston rods, the injection piston end cover, the injection piston and the injection oil cylinder body are in a same axis. The novel injection oil cylinder apparatus has the advantages of simple and effective structure, installation convenience and low price.