In the composition of pneumatic systems, pneumatic accessories play an indispensable supporting and optimizing role. They are not the core power source, but are deployed around core components (such as cylinders and pneumatic motors) to serve the overall functionality, reliability and control accuracy of the system. These accessories usually cover aspects such as pretreatment of the working medium, state monitoring, direction and flow regulation, and auxiliary control of the actuator action. Its existence is to improve the functional closed loop of the pneumatic circuit and respond to changes in medium characteristics, environmental interference and complex control logic in the actual application environment. Typical types of accessories involve purification of compressed air, pressure stabilization, motion logic sequence setting, speed control, state feedback signal generation, and safety protection under specific working conditions. Selecting and applying appropriate pneumatic accessories is a key consideration to ensure efficient, stable and safe operation of the system and achieve the expected automation performance. Its value is reflected in the optimization of the performance and adaptability of the overall pneumatic solution.