Formwork reinforcing system for double shear walls at deformation joint and construction method of formwork reinforcing system

The invention discloses a formwork reinforcing system for double shear walls at a deformation joint and a construction method of the formwork reinforcing system. The reinforcing system includes a splicing outer formwork, an inner formwork, a formwork shaping fastener installed on the splicing outer formwork, a unidirectional self-tightening opposite-pulling rod piece for reinforcing the splicing outer formwork and the inner formwork and a rebar reinforcing rod piece. During construction, firstly, a shear wall on one side of the deformation joint is constructed, the splicing outer formwork andthe inner formwork are hoisted to both sides of a to-be-poured shear wall correspondingly, PVC wall penetrating pipes are installed in reserved holes horizontally corresponding to the two formworks, the unidirectional self-tightening opposite-pulling rod piece is installed by the PVC wall penetrating pipes, the unidirectional self-tightening opposite-pulling rod piece works together with the rebarreinforcing rod piece to