Research conclusions: For the high-speed railway's traction substation 220kV lines on the power system side, the double optical fiber current differential protections should be used as the main protection configuration for the whole line, and the distance protection, current quick-breaking protection, over current protection and zero-sequence current protection should be used as the backup protection. The over thermal load protections of the 220 kV traction transformer and feeders should replace the traditional timing and limiting overload protection