Abstract: Abstract: The pH neutralization process has the highly nonlinear characteristic, when you add neutralizer or interference, pH value near the neutralization point changes a lot, while the pH value in the else points are opposite. It is very difficult to control. According to the characteristics of the pH controls in enzyme catalysis, using a parameter adaptive state controller and Hammerstein model control strategies, employing recursive least squares parameter estimation, static nonlinear characteristics of the controller upside down process non-linear part of the compensation and Hammerstein model is used to design the nonlinear model predictive control algorithm. Compared with other controller state for a difficult to control process this has a very good effect. The system engages in uncertainties real-time compensation, so as to improve the enzyme catalytic process in the stability of the enzyme activity. When the temperature random variation occurred, we carried out various controls in the field experimental study, in the enzyme-catalyzed process in the pilot test. Due to the mutual coupling of the temperature and pH in the catalytic process. The enzyme catalysis in the process of test, and the reaction time of 30 minutes and the simple PID control of the pH value of the large fluctuation, resulting in a big decrease in enzyme activity. The model reference adaptive controller under the control of the pH value of the wave is small, thus leading to a small decline in the range of enzyme activity, so as to enhance the catalytic process of the stability of the enzyme activity. In this way, converted into an approximate linear control for the pH of the enzyme catalysis process control not only enables the pH value highly nonlinear control, and automatically changes the controller tuning parameters, and solves the high degree of pH neutralization process linear control difficulties, but also improves the accuracy of the pH control in the enzyme catalysis process. pH neutralization process computer simulation results show that the control algorithm has better control over the quality to PID control. The control method can also be used for zinc smelting, in the chemical industry and other areas of pH control. The result of the typical running status indicates that the derived equations according to the theory have a prominent application value and extended significance for popularization. The control technology can be used in all kinds of chemical industry, agriculture and other areas of pH control, and can reduce the pollution of the environment, and therefore has certain market prospects.