Manufacturing method of all-welded U-shaped steel structure aqueduct

The invention discloses a method for manufacturing an all-welded U-shaped steel structure aqueduct. The method comprises the following specific steps that the steel structure aqueduct is divided into a main truss and a water tank, and the main truss and the water tank are machined and manufactured in a factory; the main truss is divided into an upper chord member (arch rib), a lower chord member (arch rib) and a web member unit according to the length of two internodes or a plurality of internodes, segmental unit pieces are manufactured in a professional factory, and the upper chord member, the lower chord member (arch rib), the web member unit and the adjacent segments are continuously matched and tried and assembled on a tried assembly platform in a field temporary processing factory; the web members and the lower chord members or the arch rib unit pieces are welded into a whole to form a composite hoisting unit; the water tank is divided into a water tank bottom plate unit and a water tank wall plate unit,