A powder gathering device for powder feeding amount measurement of thermal spraying comprises a bottle body with an opening at the top and a bottle cap which is tightly connected to the opening of the bottle body. The bottle cap is provided with a powder and gas inlet and a pure gas outlet. An airflow channel formed by at least two upper separator plates and at least one lower separator plate which are alternatively arranged and spaced is arranged inside the bottle body. With the airflow channel, airflow circulation path is greatly increased such that a powder in the airflow has enough time for settlement. Therefore, the powder can be completely separated from the airflow. Meanwhile, collision area between the airflow and the wall surface is also greatly increased. As part of kinetic energy will be lost during collision of the powder in a gas, the powder is easier to settle by increasing the collision area. According to the invention, powder gathering during powder feeding amount measurement under various conditions in a thermal spraying technology can be realized. The powder gathering device has a simple structure and is convenient for operation, implementation and powder cleaning and recovery. Problems such as severe gas and powder leakage and measurement environment pollution during simple container gathering can be avoided, and measurement accuracy of powder feeding amount can be greatly raised.