The invention discloses a retractable segment for being removed in a tunnel and a construction method. The problems of difficult removal and unrepeatable use of a shield segment are solved, and by arranging telescoping members and moving wing plates at the positions of top sealing blocks, the segment can be removed in the tunnel without breaking and can be reused. According to the technical scheme, the retractable segment comprises a plurality of standard blocks which are connected to form an arc-shaped structure in an adjacent surrounding mode, adjacent-connecting blocks are closely attachedto both ends of the arc-shaped structure, the top sealing blocks are arranged between the adjacent-connecting blocks, and the standard blocks, the adjacent-connecting blocks and the top sealing blocksconstitute a cylindrical structure; and the moving wing plates are arranged on the two sides of the top sealing blocks, the telescoping members are arranged in the top sealing blocks, the telescopingmembers are connected with the moving wing plates, and the telescoping members can drive the moving wing plates to rotate or move to abut against the adjacent-connecting blocks.