The invention provides a single-phase grounding traveling-wave protection device for a distribution line, which comprises at least one convertor inserted on a circuit substrate, a protector, a monitor and an outlet relay, wherein the convertor is used for traveling-wave signal input and power frequency signal input, and a zero-mode current traveling-wave signal, a zero-mode voltage traveling-wave signal, a power frequency current signal and a power frequency voltage signal can be obtained; the protector comprises a traveling-wave module and a power frequency module; the traveling-wave module can obtain a zero-mode current traveling wave and a zero-mode voltage traveling wave under the line frequency range of 0-100KHz; meanwhile, according to the polarity of the zero-mode current traveling wave and the zero-mode voltage traveling wave, a protection criterion is formed; the power frequency module can be used for obtaining three-phase current and zero-sequence voltage for protecting a traveling-wave module from erroneous judgement; meanwhile, the device is locked when interphase faults are caused; and the outlet relay can give a tripping signal or an alarm signal according to the requirement. According to the technical scheme disclosed by the invention, when a neutral point non-effective grounding system of the distribution line is subjected to single-phase grounding faults, the faults can be quickly and accurately detected, and reliable protection action can be performed.