This paper introduces the design of a warehouse temperature and humidity monitoring system based on a STC89C51 microcontroller. Compared with the traditional method, this system has the advantages of accuracy, sensitivity, short time and intuitiveness, and reduces the workload of the technicians and the cost of warehouse supervision. The greenhouse control system based on a microcontroller and digital temperature and humidity sensors can realize the automatic measurement and adjustment of temperature and humidity inside the greenhouse, which greatly reduces the labor intensity of operators, makes the greenhouse reach a more advanced management level, and is a low-cost, easy-to-use and accurate temperature and humidity measuring instrument, therefore it has a broad application prospect.