The invention discloses a method and system for laying bipolar direct current cables, and belongs to the technical field of operation of novel power transmission and transformation equipment. The method for laying bipolar direct current cables includes the steps: determining the distance and the number of cross-transpositions of bipolar DC cables, wherein the number of cross-transpositions is an odd number; and laying the bipolar DC cables, and performing cross-transposition on the bipolar DC cables, wherein the distance of each segment of transposition is equal to each other. In the method and system for laying bipolar direct current cables, when the DC cable are laid, cross-transposition laying is carried out on the bipolar DC cables at intervals, so that the electromotive force inducedby the external AC cables generate induced current with equal magnitude and opposite direction in the adjacent two cross-transposition segments, so as to achieve the purpose of shielding electromagnetic interference from the external AC lines.