LoRaWAN water quality magnesium ion sensor is an intelligent device that integrates low-power wide area communication and high-precision detection technology, designed specifically for monitoring magnesium ion concentration in water bodies. Equipped with professional ion selective electrodes, the measurement range is 0.01-1000mg/L, with an accuracy of ± 0.1mg/L, resistant to coexisting ion interference, and accurate and traceable data. Relying on LoRaWAN technology, the wireless transmission distance is 2-10km, and data can be collected remotely without wiring. Adopting IP68 fully sealed structure and corrosion-resistant materials, it can operate underwater for a long time and withstand complex environments such as industrial wastewater and seawater. Ultra low power design supports 3-5 years of maintenance free operation and is suitable for unmanned scenarios. Support access to mainstream IoT platforms for real-time monitoring and over limit alarms, widely used in fields such as seawater desalination, aquaculture, industrial water treatment, and environmental monitoring, providing efficient and stable magnesium ion monitoring solutions.