Abstract: There will be obvious intermittent arc discharge (potential transfer arc) in the process of equipotential live working of UHV transmission lines. The electromagnetic radiation generated by the arc may affect the normal and stable operation of the surrounding intelligent equipment. Therefore, it is of great significance to study the electromagnetic radiation characteristics of potential transfer arc. Based on the measured waveform of potential transfer current in live working of 1 000 kV AC transmission line tension tower, the frequency spectrum of potential transfer current is analyzed by Hilbert transform, and the frequency band distribution of potential transfer current is obtained. According to the antenna theory, the simulation model of electromagnetic radiation characteristics of potential transfer arc in live working is established. The radiation electromagnetic field of transfer arc is calculated, and the radiated electromagnetic field distribution of the transfer arc is obtained. The results show that the potential transfer arc current presents high-frequency oscillation with a peak value of about 1 000 A, and the main frequency is distributed in 13~20 MHz. The peak of the radiated electric field intensity generated by the transfer arc is much greater than the magnetic field intensity, both of which decay rapidly with the increase of distance, and are more concentrated near the metal conductor. When the frequency is 16.5 MHz, the maximum electric field and magnetic field intensity near the tower are about 1.5 kV/m and 1.9 A/m, respectively.