In the past few years, the traditional terrestrial wireless communication has experienced explosive growth in the number of users and the services it supports, in order to meet the growing demand of various services. However, due to the limitation of network capacity and coverage, only relying on the ground communication system cannot provide wireless access services anywhere on the earth. It is necessary to develop a new network architecture to adapt to the communication situation in different scenarios. The advantage of Space-Air-Ground integrated network (SAGIN) is that it not only has the characteristics of large satellite coverage on the earth, but also has the characteristics of small ground network propagation delay. This paper combines Space-Air-Ground integrated network with the internet of things, proposes a new network structure, and describes the characteristics and applications of this network structure in detail.