Abstract: In view of the traditional water quality monitoring system has some problems， such as monitoring nodes extension is not flexible, long distance transmission interference, etc. through the research and optimization of water quality monitoring system of data communication mode, monitoring node and sensing element, a water quality monitoring system based on IoT technology was designed. Studied the support selection of sensor deployment of monitoring nodes and gateway, water quality data was collected by monitoring nodes, the collected data through LoRa network summary and processing, and remote transmission in a timely manner to the system through GPRS network, to realize real-time monitoring of water quality situation， and the command communication and remote control of the monitoring node and gateway.