The invention discloses a hand grenade manufacturing method for training. A gunpowder mixing device is used according to the hand grenade manufacturing method for training and comprises a base and a machine body, wherein the left side of the lower end surface of the machine body is arranged on the base in an articulation manner through an articulation arm; the right side of the lower end surface of the machine body is arranged in the base through a lifting component; a rotating cavity is formed in the machine body; a rotating barrel is arranged in the rotating cavity; a mixing cavity is formedin the rotating barrel; a feeding cavity which communicates with the mixing cavity and the rotating cavity is formed in the left side of the wall of the rotating barrel; supporting shafts are symmetrically arranged at the left end and right end of the rotating barrel and are rotatably arranged in the left end wall and right end wall of the mixing cavity; a first transmission cavity is arranged atthe right side of the rotating cavity; a second transmission cavity is arranged at the right side of the transmission cavity; a center shaft which extends left and right is arranged in the left end wall and right end wall of the mixing cavity; and the left end of the center shaft sequentially penetrates the left end wall of the mixing cavity and the supporting shaft located at the left side.