Abstract: After a destructive earthquake occurs, the traditional ground communication network will be severely damaged or even paralyzed, and cannot guarantee the emergency needs of data transmission, emergency communications, command dispatch between the front and rear emergency command headquarters. In order to ensure the smooth development of the earthquake emergency command, a safe and reliable communication system is needed. The BeiDou Navigation Satellite System (BDS) independently developed by China is a global satellite navigation system. It has functions such as precise positioning and navigation, precise timing, and short message communication. It can play an important role in disaster emergency management. Therefore, starting from the needs of emergency work at the earthquake site, and on the basis of analyzes various communication technologies, research and explores a field communication system for seismic emergency based on BeiDou Navigation Satellite System to meet the emergency needs of the earthquake site, such as requirements of rapid acquisition of disaster information, accurate location of disaster areas, and real-time transmission of disaster reports, etc. It is used to ensure the smooth and unimpeded communication at the earthquake site and ensure that emergency command is carried out smoothly.