The invention provides a vertical composite welding method for Q690qE high-strength steel for a bridge. The method comprises the steps that during welding, a welding groove is machined and cleaned atfirst, the groove is in a V shape, and the angle of the groove is 48-52 degrees; assembling is conducted through a clamping plate, the gap of the minimum position of the groove is controlled to 4-8 mm, and the back surface of the gap is provided with a ceramic liner; then, a steel plate is preheated to 70-80 DEG C; base coat welding is conducted through solid wire argon-rich gas shielded welding;filling and cover surface welding are conducted through alkaline flux-cored wire carbon dioxide gas protection; and finally, the steel plate is subjected to heat preservation and cooling deceleratingto the normal temperature through heat preservation cotton. The Q690qE high-strength steel for the bridge has the advantages of being good in welding quality, excellent in joint mechanical property and high in welding efficiency.