The invention discloses a method for detecting the safe power-line-cruising distance of a UAV (unmanned aerial vehicle), which comprises the following steps of: (1) carrying out analysis according to the characteristics of electromagnetic fields of to-be-detected high-tension transmission lines in different
voltage levels, and establishing corresponding electromagnetic-
field simulation calculation models; (2) determining the maximum errors of electronic devices (which are susceptible to
electromagnetic interference) carried by the power-line-cruising UAV and measuring devices used in the process of
route planning making before routing inspection; (3) according to the requirements of the determined electronic devices on electromagnetic fields in the process of normal operating, by using the electromagnetic-
field simulation calculation models of the high-tension transmission lines in different
voltage levels and electromagnetic-
field simulation calculation
software, calculating the similarities and differences of an
electromagnetic environment when the UAV has different distances away from a transmission conductor in the process of carrying out line-cruising operation on each high-tension
transmission line, thereby determining the range of the safe distance between the UAV and the transmission conductor; and (4) carrying out line-cruising by the UAV according to the determined safe distance of each to-be-detected
transmission line, thereby avoiding the situations that the devices run disorderly, the flight communication is interfered, a flight mission is failed, and the like caused by the
electromagnetic field of the transmission conductor, and then ensuring the safety, stability and reliability of a flight.