Pond aquaculture is sensitive to the real-time water quality, so strict requirements are put forward for the water quality monitoring system. A heterogeneous sensor network water quality monitoring system based on the LoRa protocol and ZigBee protocol is designed for the complex field environment of pond aquaculture. The system uses water quality monitoring sensors and heterogeneous wireless sensor network to collect and transmit dissolved oxygen, pH, and water temperature. Remote data storage and monitoring are realized through the cloud server platform. The test system was set up in the field environment with a communication distance of up to 5 km for experiment. After 30 d of simulated work test, the water quality monitoring system designed in this study has the advantages of wide monitoring range, low construction cost and stable operation. The maximum variance of measurement error is 3.88% and of the time delay error is less than 1%, which can fully meet the needs of water quality monitoring in pond aquaculture.