The invention relates to methods for positioning a safety brake disc on a reel of a vertical ship lift and adjusting end face runout. An annular positioning boss is arranged on the safety brake disc,an annular notch is formed in the outer surface of a reel barrel, and the annular positioning boss and the annular notch are in clearance fit. The method for positioning the safety brake disc comprises the following steps: firstly, assembling an annular positioning boss on the annular notch, wherein the annular positioning boss and the annular notch are in clearance fit; then rotating the safety brake disc to enable second reaming holes to correspond to first reaming holes one by one, putting shear sleeves into the second reaming holes and the first reaming holes, and then connecting the safety brake disc and a reel spoke plate together through a high-strength bolt so as to complete the radial and axial positioning of the safety brake disc. The method for adjusting the end face runout of the safety brake disc comprises the following step that the clearance between the end face of the safety brake disc and the end face of the reel spoke plate is adjusted by adjusting the tightness of the high-strength bolt, so that the local adjustment of the end face runout of the safety brake disc is realized.