The invention provides a fault arc detection method based on a high frequency characteristic and an apparatus thereof. The apparatus comprises a voltage zero-crossing detection unit, a current waveform acquisition unit, a current filtering shaping unit, a detection analysis unit, a liquid crystal display unit, an acousto-optic warning unit, a control unit and a communication unit. The detection analysis unit collects a pulse signal output by the current filtering shaping unit and original current data output by the current waveform acquisition unit through high speed I / O and A / D respectively. A pulse density and a current time domain characteristic are combined and used to analyze and determine a fault arc. When the fault arc is detected, an acousto-optic alarm and trip signal is emitted. By using the detection method, the fault arcs of various kinds of loads of a subordinate branch can be identified and are not influenced by superior or other parallel branch fault arcs. Sensitivity is high and a false alarm rate is low. In addition, according to different applications, software and hardware parameters are only configured and a circuit structure does not need to be adjusted; the method and the apparatus can adapt to alternating current / direct current arc detection and a plurality of standards, and versatility is good.