Pulp and paper making is an indispensable part of the paper-making process, and it plays a crucial role in the quality and cost of paper. Chemical aids refer to a general term for small amounts of chemical substances added to the main materials to improve certain properties of pulp or paper, reduce material consumption and optimize operating conditions. They can be divided into pulping aids, paper-making aids, coating and processing paper aids, etc. Therefore, high requirements are put forward for the accuracy, operability and stability of the aid dosing device.