The invention discloses an externally-wrapped steel plate reinforced concrete assembled shear wall and a construction method thereof. The exterior steel plate reinforced concrete assembled shear wall is provided with an externally-wrapped steel plate wall body, concrete and a plurality of stirrup pairs located in an inner cavity of the externally-wrapped steel plate wall body. Each stirrup pair comprises first stirrups and second stirrups, and the first stirrups and second stirrups are provided with welding sections and protruded sections equal in number; all the welding sections of the first stirrups are welded onto the inner side face of a first steel plate wall surface, and all the welding sections of the second stirrups are welded onto the inner side face of a second steel plate wall surface; all the protruded sections of the first stirrups correspond to the protruded sections of the second stirrups one to one, and part of an enclosed area of the protruded sections of the first stirrups is overlapped with part of an enclosed area of the protruded sections of the second stirrups in the vertical direction. According to the externally-wrapped steel plate reinforced concrete assembled shear wall and the construction method thereof, the opposite-pull effect between the two steel plate walls can be achieved through a few welding workloads, brittle failure of the concrete can be effectively restrained from occurring, earthquake-resistant ductility of the shear wall is greatly improved, and the externally-wrapped steel plate reinforced concrete assembled shear wall and the construction method thereof have the advantages that steel consumption is little, and manufacturing cost can be reduced.