Abstract: When UHV AC and DC lines run in the same corridor, the voltage in the live working area is high and the field is strong. The AC/DC mixed electric field is more complex than a single electric field. In order to ensure the safety of workers, combined with the actual ±1 100 kV DC and 1 000 kV AC lines, a three-dimensional calculation model including transmission lines, towers and live working personnel is established in this paper. Through the analysis of the mixed field strength, potential transfer current and transient energy on the body surface of workers during live working, the safety protection of workers is studied. The results show that as the operators approach the DC line, the field strength on the body surface is more obviously affected by the AC line, which can increase the field strength on the body surface of the operators by about 9% to 1 920 kV/m at most. The existence of AC line will increase the potential transfer current by about 7%, but has little effect on transient energy. Through the further calculation of carbon emissions reduced by non-power outage maintenance of UHV lines, it is verified that UHV live working has a promoting effect on reducing carbon emissions.