The present invention relates to a device for positioning submarine pipeline robots and method. The device comprises a pressure wave generator and a device for pressure wave acquiring and processing. The method comprises the following steps of (1) determining the generation mode; (2) acquiring pressure signals; (3) filtering pressure signals; (4) dividing the filtered pressure signals of into the same group; (5) identifying the data during this period in real time; (6) determining the moving state of the robot in the pipeline; (7) calculating the position of the robot in the pipeline; (8) ending the operations, otherwise repeating Step 4 to Step 7 continuously. The present invention has the advantages that the position of submarine pipeline robots can be located in real time. In addition, the severe environment around the pipelines can hardly affect the performance under this method.