Controlling CO₂ concentration in greenhouse can enhance photosynthetic efficiency and improve crop yield and quality. Refer to the equipment that is used to create chemical reaction between liquid and solid, an intelligent release system of CO₂ concentration was designed by controlling the reaction speed that is connected with liquid reactants. According to the working principle of medical liquid syringe, a liquid controller with good air gas tightness was designed. And liquid was input to the gas-producing reaction device which located in the middle of the in-fusion pipe. In the middle of the gas production device, solid carbonate was added, which reacts with dilute sulfuric acid or dilute hydrochloric acid flowing into the liquid to produce CO₂ gas. On the other side of the reactor is a gas washing device, which removes impurities from the CO₂ gas and then sends it to the greenhouse through a gas pipe-line. Combined with the use of greenhouse CO₂ concentration detection instrument, a set of CO₂ intelligent release system is formed by intelligent control.