The current protection setting calculation of wind farm feeder lines is based on sensitivity setting at the end of the feeder line. It will result in high sensitivity and low selectivity of the protection when a weak power grid is connected and the feeder line is longer. Thus there is a risk of relay protection mis-operation. First, this paper analyzes the influence of low voltage ride-through on the short-circuit current of wind turbines, and studies the main factors affecting the short-circuit current of wind turbines. Secondly, a typical relay protection configuration of the wind farm is introduced. The protection areas in a wind farm are divided. The protection configuration rules of feeder line current protection are studied. Then the risk of protection mis-operation of the feeder line current protection of wind farm is analyzed. The causes of the mis-operation of the feeder line current protection are studied during the feeder head-end wind turbine fault or the adjacent feeder lines head-end fault. Based on the above theoretical analysis, a secondary verification method for the current protection setting calculation of the wind farm feeder lines is proposed and a calculation example is given. This work is supported by National Natural Science Foundation of China (No. 51307059).