The invention relates to a single-ended current sudden change phase selection method. The method comprises steps that criteria of a sudden change current phase selection relay are constructed; sudden change current phase selection criteria with high sensitivity and low sensitivity are constructed ; fault phases are selected through matching the sudden change current phase selection criteria with high sensitivity and low sensitivity. The method is advantaged in that based on single-ended current sudden change, the fault phases are selected through matching different sensitivities, the method further has high sensitivity, and the method is slightly influenced by a load component and a transition resistor.