Embodiments of the invention disclose a same-routing cable fault location method. The method is characterized by comprising the following steps of obtaining a standard same-routing cable fault sample corresponding to a transport network; inputting the standard same-routing cable fault sample into an SOM neural network to learn and obtaining a mark area of an output layer of the SOM neural network; and determining location information of a faulted same-routing cable repeater section. The embodiments of the invention also disclose a same-routing cable fault location device.