The invention discloses a middle partition wall structure for a tunnel, comprising at least two tunnel pipes and at least two middle partition walls. The middle partition walls are arranged in the tunnel pipes and are connected with the tunnel pipes by one end; the middle partition walls are in the prefabricated reinforced concrete structures; and middle partition walls are as long as the tunnel pipes along the extension direction of the tunnel. Because the middle partition walls are in the prefabricated reinforced concrete structures, the middle partition walls can be assembled and constructed conveniently. Because the middle partition walls are as long as the tunnel pipes, the connection stiffness of the tunnel can not be changed, and the seismic performance of the tunnel can be ensured.