An anti-deformation assembly line, comprising an assembly base (100), a moulding bed (200), a travelling mechanism (300), a counter-force hook (400) and stress application mechanisms (500). The assembly base (100) comprises guide rails (110), which are arranged symmetrically, and a support frame (120) arranged between two guide rails (110). The moulding bed (200) is arranged on the support frame (120), and can be flipped relative to the support frame (120). Clamps (210) are provided on two side edges of the moulding bed (200). The travelling mechanism (300) comprises travelling trolleys (310), which are arranged on the guide rails (110) and can move along the guide rails (110), and a transverse beam arranged between two travelling trolleys (310). The counter-force hook (400) comprises connecting assemblies, hook members (420) and guide rail connecting assemblies (430), which are symmetrically arranged on two side edges of a housing of a prestress application device. Each guide rail connecting assembly (430) comprises a plurality of connecting plates (410), which are perpendicular to a side edge of the travelling trolleys (310) and are parallel to each other. The stress application mechanisms (500) are symmetrically arranged at the bottom of the transverse beam (320), and apply stress to a steel bridge deck plate arranged on the moulding bed (200). The anti-deformation assembly line can prevent the assembly base from being damaged.