In order to enhance the traditional Chinese medicine preparation the product quality and the production efficiency, the design suits the traditional Chinese medicine preparation automatic extraction the PID control system. Introduced that the PID control theory and the traditional Chinese medicine preparation's control flow, through carries on the different period in the traditional Chinese medicine preparation automatic foliation to the regulating valve the PID control, causes the clamp cover pressure maintains in stably the setting value, thus causes in the reaction still the solution temperature, in the different craft stage maintains under the different temperature condition. This system has succeeded applies withdraws and has made the good progress automatically in the enterprise traditional Chinese medicine preparation.