This paper proposes a new mode of online safety monitoring system construction of tailings dam based on the internet of things, which can solve the problem of current mode, such as high investment, high cost of maintenance shortcomings, redundant construction, low utilization rate of resources. It has abandoned the traditional "sensor + data acquisition station+ server" construction mode. Combined with the cloud service technology, the "internet of things sensor + cloud service + terminal" construction concept is put forward, and its feasibility is verified by an example.