When the high voltage transmission line is non-full-phases operation, the asymmetric element will be closed. While the healthy phases of the line have faults under such circumstances, if the voltage of swing center continuous low is the only criterion for fault detection, it needs long time-delay and will impact the speed of distance protection trip. Moreover, this scheme is not suitable for single-phase earth fault. The paper proposes a combining scheme that, single-phase fault can be detected through partition changes of phase selection by zero-sequence current and negative-sequence current phase selector, and phase-to-phase fault can be detected through the delta voltage of swing center, when power system is non-full-phases and swing operation. The simulation results show the effectiveness of the scheme.