A large number of power transmission lines in Sichuan power grid are in no-man's land with complex terrain and blocked communication. The inspection of transmission lines is usually difficult and risky. Online monitoring data transmission technology takes advantage of that the beidou satellite communication system is not affected by geographical environment and communication network stations, realize real-time two-way short message communication in no man's land, automatic navigation and positioning, SOS distress, etc. This technology is helpful to realize the real-time intelligent line status record in the process of power grid inspection, guarantee the safety of power grid inspection and improve the efficiency of power grid management system.