The utility model discloses a support top bracket for supporting steel case arched bridge, including braced system, braced system includes bottom steel sheet, horizontal basic steel seat, vertical braces steel construction group and diagonal bracing steel construction group, horizontal basic steel seat interval parallel connection is on the steel sheet of bottom, the higher authority of horizontalbasic steel seat is connected with perpendicularly vertical braces steel construction group, be connected with diagonal bracing steel construction group above the vertical braces steel construction group, the line type phase -match of diagonal bracing steel construction group's top surface and steel case arched bridge bottom surface, the centre of vertical braces steel construction group and diagonal bracing steel construction group is provided with the governing system who is used for guaranteeing the arch rib accurate adjustment. Through the utility model discloses to the support of steel case arch rib, can, the butt joint of steel case arch rib restrict its skew that arouses because of the dead weight after accomplishing.