The UHVDC transmission line between Hami and Zhengzhou needs the same corridor with other twocircuit UHVDC transmission lines. In the threecircuit UHVDC transmission lines with the same corridor, total electric field strength in the ground, the radio interference and audible noise are analyzed. In addition, the width of transmission line corridor and demolition range are obtained under the electromagnetic environment requirements, providing references for the design and maintenance practice of overhead lines.