Abstract: Aiming at the problems of low flexibility and high maintenance cost for the upgrade and maintenance of the Internet of Things terminal software in agricultural greenhouses, and low intellectualization of environmental monitoring in the greenhouses, an agricultural greenhouses measurement and control system based on Harmony OS and OTA technology（Over-The-Air technology） was researched and designed. To ensure the validity and integrity of the OTA file and improve the security of the system, the signature and verification processes are added during the OTA firmware upgrade process. In this study, the Hi3861 WLAN module equipped with Harmony OS, combined with the environmental parameter sensor module and the OLED display module, realizes the real-time acquisition and display of environmental parameters such as air temperature and humidity, light intensity, and carbon dioxide concentration. Using WiFi communication combined with MQTT（Message Queuing Telemetry Transport） protocol, the Web device management system based on Django and the terminal device based on Harmony OS were combined. The greenhouse environment data can be viewed, the greenhouse facilities can be controlled accordingly, and the OTA firmware upgrade of the terminal equipment can be carried out. The test results show that the system can effectively complete the real-time monitoring of the agricultural greenhouse air temperature, air humidity, light intensity, carbon dioxide concentration, and other environmental data, and can remotely monitor and control the agricultural greenhouse through the Web equipment management system, and can perform OTA firmware upgrade of the terminal equipment.