The safe and real-time monitoring of the production process of acetic acid is always a key technical problem. The conventional online chromatographic analysis can’t satisfy the requirements of real-time analysis for its inherent disadvantages. A new type of on-line near-infrared analysis system has been developed for real-time analysis of the concentration of each component in acetic acid reaction kettles instantly. Its features and configuration were described in detail. Both the laboratory modeling and field application results have confirmed that this system is of high stability and accuracy. The proposed system can effectively solve the key technical problems in the manufacture and ensure the safety and stability of production process of acetic acid.