The invention discloses a testing system for the scouring corrosion of a bending pipe and a testing method. The testing system comprises a water tank, wherein an outlet of the water tank is connected with a centrifugal pump by a pipeline, and a ball valve is arranged on the pipeline between the water tank and the centrifugal pump; the output end of the centrifugal pump is connected with one end of the bending pipe to be tested by a straight pipeline, and the other end of the bending pipe to be tested is connected into an inlet of the water tank by a pipeline; a flow meter is arranged on a connecting pipeline between the bending pipe to be tested and the water tank; the inner wall of the bending pipe to be tested is provided with a plurality of grooves at different positions along the circumferential direction and the axial direction; the bottom parts of the grooves are provided with line holes for educing testing guide lines; the wall of the bending pipe to be tested is provided with two round holes which are respectively provided with an auxiliary electrode and a reference electrode. The testing system and the testing method disclosed by the invention have the advantages that the inner wall of the bending pipe to be tested is provided with the plurality of grooves and piece hanging can be carried out on different small areas of the bending pipe to be tested, so that the synchronous conduction of weight-loss test and electrochemical test for the scouring corrosion of the bending pipe to be tested is realized.