The relationship between the operation mode of double circuit lines on the same tower（DLST） and the zero sequence current compensation coefficient（ZSCC） is analyzed.It's evident that the fixed ZSCC adopted in the conventional setting method is unable to guarantee ground distance protection obtain higher sensitivity under double lines normal operation mode and better selectivity under single line operation mode. To improve the performance of ground distance protection， setting value section switching function of microcomputer protection is proposed in setting calculation， which selects the suitable ZSCC according to operation mode to eliminate the effect of operation mode on the measured impedance. Finally， the validity of this scheme has been verified by ATP simulation software， with the model of an actual 750 kV DLST in northwest grid of China.