The invention discloses a reinforced concrete shear wall and a construction method thereof, and belongs to the technical field of civil engineering construction. The reinforced concrete shear wall comprises a first fixing plate, wherein the top of the first fixing plate is connected with a supporting rod, the top of the supporting rod is connected with a cylinder, the output end of the cylinder isconnected with a pull rod, a through hole matched with the pull rod is formed in the top of the first fixing plate, the end, away from the cylinder, of the pull rod penetrates through the through hole and is connected with a connecting box, connecting rods are rotationally connected to the inner walls of the two sides of the connecting box, second fixing plates are fixedly connected to the two ends of the first fixing plate, sliding plates are slidably connected to the outer walls of the two second fixing plates, the ends, away from the connecting box, of the connecting rods are connected with the sliding plates, clamping plates are connected to the bottoms of the sliding plates, and wood formworks are connected to the outer walls of the clamping plates. According to the invention, the cylinder is used for controlling the clamping plates to clamp the wood formworks, the clamping distance between the wood formworks can be adjusted, the use requirement is met, nails are not needed for fixing, and dismounting and mounting are convenient.