The invention discloses a barge landing and launching method. The barge landing and launching method comprises the following steps of laying two horizontal steel rails and two oblique steel rails; mounting a triangular trolley on the two oblique steel rails, moving a horizontal trolley to the top of the triangular trolley, and then launching the horizontal trolley and the triangular trolley to positions under the water surface along the oblique steel rails together, and guaranteeing that the height difference between the top of the horizontal trolley and the water surface is larger than the draught of a barge; sailing the barge to a position right above the oblique steel rails; pulling the triangular trolley to move upwards along the oblique steel rails by using a winch so that the triangular trolley and the horizontal trolley moves to positions under the barge together, and enabling the bottom of the barge to be in contact with the top surface of the horizontal trolley; pulling the triangular trolley and the horizontal trolley in sequence so that the barge reaches a steel beam machining workshop; pulling the horizontal trolley and the triangular trolley in sequence; and after thetriangular trolley is launched in place, enabling the barge begins to float. Through adoption of the barge landing and launching method, large steel beams and steel members can be directly shipped inmachining workshops.