An intracorporeal assembled device for minimally invasive surgery is provided. The intracorporeal assembled device for minimally invasive surgery is applied to a laparoscopic surgery and includes a hand piece and a surgical piece. The hand piece has a handle portion, the handle portion has a pipe portion, the pipe portion has a first diameter, and a first connection portion is disposed to one end of the pipe portion. The surgical piece has a second diameter, a second connection portion corresponding to the first connection portion is disposed to one end of the surgical piece, and a workpiece is disposed to one other end of the surgical piece. The first diameter is smaller than the second diameter, and the surgical piece is connected to the pipe portion in a detachable manner via the first connection portion and the second connection portion.