The invention provides an aerial steel platform for achieving the continuous construction of an overlapped tunnel and a construction method thereof. The overlapped tunnel comprises a working well, a ring beam, a lower-layer tunnel body and an upper-layer tunnel body, wherein the ring beam is formed on the inner wall of the working well, and the lower-layer tunnel body and the upper-layer tunnel body are formed on the lower and upper sides of the ring beam; the reception of the lower-layer tunnel body is completed in a shield, turning and building formation after starting of the steel platform are completed in the working well; in this way, after building of the steel platform is completed, the construction of the lower-layer tunnel body can be restored subsequently, the construction of the upper-layer tunnel body such as starting, tuning and receiving is conducted at the same time, and the difficulty is solved that existing up-and-down overlapped tunnels can not be continuously constructed. By the adoption of the aerial steel platform for achieving the continuous construction of the overlapped tunnel, tunnel-door ring beam and filling concrete pouring and hoisting construction of large equipment on the late stage of tunnel construction are not affected.