With the wide application of the Internet of Things in smart cities, people's awareness of infrastructure protection has been further improved. How to efficiently and accurately operate all kinds of pipe networks and protect the long-term availability of pipe network facilities is the focus of operators at all levels. This paper introduces the popularization and application of smart manhole covers as one of the important facilities for operators to operate underground pipelines under the NB -IoT model from the perspective of construction and maintenance, Through the Internet of Things technology, cloud computing technology, mobile Internet technology and related sensor products, it helps the competent department of the operator's pipe network to find the abnormal state of the manhole cover at the first time and create conditions for timely maintenance. At the same time, through the actual application model and commercial situation, the development prospects of the theory and practical effects of this model in other areas of the Internet of Things are further expounded.