Beidou RDSS has an advantagement of short-text-message communication. It can cover a large area, especially suitable for emergency communication in special situations such as isolated islands and deep mountains. It can obtain important data for dealing with emergencies. Based on the characteristics of Beidou RDSS short-text-message communication and the randomness of data in nuclear radiation monitoring industry, a method of Beidou emergency communication is proposed to coordinate the frequency of monitoring data and Beidou message frequency, which improves the communication emergency capability and intelligence of Radiation Monitoring System (RMS).