An underground localization method and a system therefor are provided. The underground localization method includes computing location information of a dead reckoning using a gyro sensor and a distance movement sensor of moving equipment, measuring physical information according to the computed location information of the dead reckoning and searching for the physical information which is determined as being matched with the location information of the dead reckoning, and optimizing a location by reflecting location information of the physical information which is determined as being matched with the location information of the dead reckoning.