Abstract: An IoT water purification system includes a water purification device and a cloud management device. The water purification device includes a filter element, a water tank, a water quantity sensing circuit, a filter element sensing circuit, and a water purification side wireless transmission circuit. The water quantity sensing circuit measures a current storage quantity of the drinking water to generate respective water quantity information. The filter element sensing circuit measures a water quality of the tap water to generate water quality information. The cloud management device includes a cloud wireless transmission circuit and a cloud processing circuit.