Shield tunneling machine in-tunnel turning-around system

The utility model relates to an in-tunnel turning system of a shield tunneling machine. A shield tunneling machine U-turn area is narrow in site and limited in space, collision between the shield tunneling machine and a side wall is easily caused, and the construction progress and safety are affected. The system comprises a left line shield tunnel, a right line shield tunnel, a U-turn hoisting channel and two shield equipment storage channels. The front section of the U-turn lifting channel is a shield U-turn section, and the rear section of the U-turn lifting channel is a lifting equipment operation section; the whole system is arranged in an I shape on the plane, the left line shield tunnel and the right line shield tunnel are connected into the shield U-turn section in parallel, and the hoisting equipment operation section is connected into the two shield equipment storage channels arranged in parallel. The cross section outline of the turning-around lifting channel is located on the outer side of the cros