There is an “one switch” method in the water management in larger institutions, not focusing enough on internal control, and the essence is the lack of good monitoring method. The paper proposes a random measurement system of water consumption based on mix network of ZigBee and NB-IoT, consists of two components called detecting node and cooperative node. The system can realize the functions of detection and transmission of the parameters such as flow, velocity, time, frequency, failure etc., then data will be uploaded to the IoT platform. Experiment results show that system performance is effective and utility and can provide an effective assessment for strategy of using water.