The invention provides a highly-adaptive power transmission line fault location method and system. The method includes the following steps that: three-phase current generated after a fault of a powertransmission line occurs is extracted, modulus transformation is performed on the three-phase current, so that a linear modulus can be obtained; multi-scale transformation is performed on the linear modulus, and fault initial time points at two ends of the power transmission line are positioned; time delay is calculated according to the fault initial time points at the two ends of the power transmission line; the forward cross-correlation sequence and reverse cross-correlation sequence of the two ends of the power transmission line are determined according to a wavelet transformation scale andthe time delay; fault point reflected waves and/or bus-bar reflected waves are identified according to the forward cross-correlation sequence and reverse cross-correlation sequence at the two ends ofthe power transmission line; and fault location calculation is performed according to the identified fault point reflected waves and/or bus-bar reflected waves. According to the highly-adaptive powertransmission line fault location method and system provided by the technical schemes of the invention, the identification success rate of the fault point/bus-bar reflected waves is improved through the time-frequency correlation of the data at the two ends of the power transmission line, and line length and timing error are corrected on the basis of the improved identification success rate, and therefore, the adaptability and precision of fault location are improved.