Abstract: Compared with traditional soil cultivation, hydroponics can make crops grow faster and reduce pests. As the crops continue to absorb nutrients from the nutrient solution, the water quality parameters of the hydroponic nutrient solution need to be monitored in a timely and accurate manner, and nutrients are supplemented as needed. This paper designs and tests an intelligent monitoring system based on the Narrowband Internet of Things（NB-IoT） for the growth process of hydroponic lettuce, Real-time monitoring of hydroponic environmental parameters through the user interface of WeChat, combined with fuzzy control methods, adjusting water quality parameters of nutrient solution based on expert experience and crop needs. It can be seen from the test results that the average packet loss rate of data communication in this system is 0.76%. When adjusting the nutrient solution with an initial pH of 7.3 and conductivity of 1.2 mS/cm, the pH and conductivity will maintain stable preset values after 68 s and 63 s, respectively. The intelligent monitoring system can stably maintain the water quality parameters of the nutrient solution within the range beneficial to crop growth during the crop growth cycle.