As a new voltage class in China, the ground clearances and crossing clearance of the ±1 100 kV transmission line have significant impacts on project cost, which is one of the key technical principles in transmission line design. Based on the design and operation experience of ±800 kV UHVDC transmission line, the determining principle was suggested for the ground clearance and crossing clearance of conductors in ±1 100 kV UHVDC transmission line. The electric field effects were calculated and analyzed at different section of conductors with different split number, split spacing, electrode spacing and ground clearance. In the end, combined with the design and operation experiences of ±800 kV HVDC transmission line, this paper presented the crossing clearance and corridor width of conductors in ±1 100 kV UHVDC transmission line, which could provide reference for further engineering design.