Powder spraying device capable of achieving pressure relief and accurately controlling spraying amount

The invention discloses a powder spraying device capable of achieving pressure relief and accurately controlling the spraying amount. The powder spraying device comprises a machine base. A dividing part is arranged in the middle of the machine base, and the interior of the machine base is divided into a stock bin and a mixing bin. A blanking opening is formed in the dividing part and is connectedwith the stock bin and the mixing bin. An inserting groove is formed in the dividing part in the horizontal direction, a sliding quantitative baffle is arranged in the inserting groove, and a quantitative opening is formed in the sliding quantitative baffle. A pull rod is arranged at the tail end of the sliding quantitative baffle, a high-pressure air inlet pipe is arranged on the side edge of themixing bin and connected with an air distributing part, and the air distributing part is provided with an air spraying pipe and a constant-pressure pipe. The air spraying pipe is inserted into the mixing bin, and the constant