Prefabricated shear wall, shear wall system and construction method of shear wall system

The invention belongs to the technical field of fabricated buildings, particularly relates to a prefabricated shear wall, a shear wall system and a construction method thereof, and aims to solve the problems that in the prior art, the construction speed of a prefabricated shear wall is low, and the construction quality is difficult to guarantee. According to the prefabricated shear wall, the shear wall system and the construction method thereof, connecting grooves are vertically formed in the two sides of the prefabricated shear wall, transverse steel bars in the prefabricated shear wall extend out of the side faces and form U-shaped lap joint steel bars located outside the connecting grooves, transverse grooves are formed in the bottom of the prefabricated shear wall, and buttresses are arranged in the transverse grooves, the buttresses protrude outwards in the height direction of the prefabricated shear wall and extend out of the transverse grooves, the two ends of the transverse grooves communicate with th