Development of automatic monitoring of anaerobic fermentation operational stability is insufficient. An automatic system for monitoring total volatile fatty acids (VFAs) and alkalinity in term of total inorganic carbon (TIC) was designed by following the principle of Nordmann titration method and industrial process computer. The software was designed with platform of Visual Studio 2017 and C# programming after analyzing its functions. The whole system was divided into nine units, including data-sending unit, chifecontrol unit, monitoring unit, moving-control unit, titration unit, cleaning unit, sample-adding unit, I/O control unit and data-collecting unit. It can not only accurately measure the concentration of VFAs and TIC, but also send the results and suggestion to users through internet. Furthermore, all above nine units completed and made sure they communicate each other successfully, testing and verifying accuracy and precision through series experiments. The experimental results showed that both accuracy and precision of this system were over than 95% in test of digested chicken manure, which was higher than the results from manual titration. The results indicated that this automatic system would have an important practical application for biogas projects.