The invention provides a gas spraying head for a vacuum pre-loading gas pressure splitting system. The gas spraying head comprises a gas spraying head main body 1 and a switching joint 2 for connecting the main body 1 to a gas injection pipe 3, wherein the front end of the gas spraying head main body 1 is conical; holes 4 are distributed in the gas spraying head main body 1; the switching joint 2 is flatly cylindrical, and a through hole through which the gas injection pipe 3 passes is formed in the middle of the switching joint 2; a plurality of circular holes are formed in the peripheral edge of the side surface of the switching joint 2; bolt rods 5 pass through the circular holes; and the front end of each bolt rod 5 is fixedly connected with a barrier plate. The gas spraying head has the advantage of high efficiency.