Based on USTC'S IaaS cloud platform, this paper designs and implements WSN's real-time monitoring system. The 6LoWPAN is used to build wireless self-organized sensor network, and each sensor node in system transmits data collected by sensors to sink node, then the sink node sends data to the server on USTC's cloud platform through network to record and analyze. In this paper, we adopt Nginx as a web server, and the non-real-time and real-time data is handled by uWSGI application server and Tornado application server respectively. The WebSocket technology is used to achieve real-time data transmission which improves the performance of system in real-time. The test results show that this paper has a certain guiding significance for the construction of real-time monitoring system with good reliability and flexible deployment.