The invention discloses an overcoming method for drawing defects of a large length-width ratio flat tube part. The overcoming method comprises the steps of designing a technological model of part drawing forming according to a theoretical model of the part; optimizing and designing a spreading raw material according to the technological model to ensure that the fiber direction of the plate material of the part keeps parallel to the length direction of the part; manufacturing a primary profile similar to the shape of a flanged side according to the principle that the arc lengths of the theoretical model in the length and width directions are the same before and after shaping; externally extending and protruding central regions of the two ends of the primary profile in the length direction as compensation excess materials; adding friction layers on the upper and lower surfaces of the compensation excess materials at the two ends of the spreading raw material; and finally, putting the spreading raw material on a mold manufactured according to the technological model to be subjected to drawing forming.