The invention relates to a touch-sliding type power supply system for a gantry crane. The system comprises a column of vertical supporting rods parallel to a gantry crane rail; a longitudinal beam isfixedly connected to the upper ends of the vertical supporting rods and is connected to a plurality of transverse supporting rods; four sliding grooves are connected to the bottom of each transverse supporting rod; openings of the sliding grooves are downward; a conductive metal strip and two conductive metal sheets are arranged in each sliding groove; a three-phase cable and a null line are led out of a gantry crane distribution box and are connected to conductive plugs correspondingly; the conductive plugs are arranged in the sliding grooved in a clamped mode and can slide in the sliding grooves in a reciprocating mode; the bottom of each plug is connected to a plug protective sleeve; U-shaped connecting parts are connected to the two sides of each plug protective sleeve separately through rotating shafts; a tripod which is horizontally arranged is arranged on a gantry crane ground beam and is fixedly connected to a pull rod; and the pull rod is connected to the four U-shaped connecting parts through four connecting rods.