Screw machine barrel of injection molding machine

The utility model provides a screw cylinder of an injection molding machine. The screw cylinder solves the problem that an existing screw cannot well mix molten materials in the cylinder uniformly. The screw rod is sequentially provided with a feeding section, a melting section, a first mixing section, a homogenizing section, a second mixing section and a discharging section in the feeding direction, the first mixing section comprises a first mixing section and a second mixing section which are spaced from each other, first grooves are uniformly distributed in the circumferential direction of the first mixing section, second grooves are uniformly distributed in the circumferential direction of the second mixing section, and the first mixing section and the second mixing section are communicated with each other; the first grooves and the second grooves are arranged in a staggered mode, and at least two sets of rhombic protruding blocks which are arranged in a staggered mode are arranged in the circumferential