Shield tail performance monitoring and emergency device of shield tunneling machine

A shield tail performance monitoring and emergency device of a shield tunneling machine is characterized in that a sealing cavity is formed between two adjacent annular sealing brushes, the sealing cavity is filled with grease used for sealing, an annular airtight rubber ring is further arranged in the sealing cavity, and the airtight rubber ring is fixed to the position, located between the two adjacent annular sealing brushes, of the inner wall of a shield tail in a surrounding mode; the airtight rubber ring is provided with an annular hollow inner cavity, a plurality of pressure sensors are evenly distributed on the airtight rubber ring in the annular direction of the airtight rubber ring, and the pressure sensors are arranged in or outside the hollow inner cavity of the airtight rubber ring, evenly distributed in the annular direction of the airtight rubber ring and connected with a monitoring control unit arranged outside the sealing cavity. And an inflation inlet is formed in the airtight rubber ring. T