This paper analyzes the present situation and difficulties of yak breeding in the “Three Needy Autonomous Regions” of Sichuan Province, integrating the specific natural environments of Qinghai-Tibet Plateau. Research work focuses on the requirements of no network conditions, large-scale application, and ultralow use cost. We propose a smart grazing IoT system, in which collars and ear-tags are designed to collect the positions and physiological signs of yaks, BeiDou Satellite-Base Stations (BDS-BSs) are designed to build local area network and ultralong-distance communication, and what is more, UAV is designed to expand the communication range to hundreds of kilometers. According to the actual needs of grazing monitoring, we propose an effective data reduction method, so that BeiDou Satellite (BDS) short-message technology can be applied to the IoT communication with high efficiency and low cost. The author carried out a significant number of experiments and verification: (1) collar realized positioning and physiological signs collecting of yaks. (2) The local area network (LAN) scheme based on LoRa built a stable communication distance of more than 3 km. (3) Ultralong-distance communication scheme based on BDS short-message technology effectively solved the problem of no network and got excellent zero additional use cost. (4) A plateau mountainous grazing UAV is designed and developed to expand the communication range.