The invention discloses a shield tunnel lining segment and further discloses a reinforcing method of the shield tunnel lining segment. An existing structure comprises a top-sealing block, a first adjoining block, a second adjoining block, a bottom-sealing block, a first standard block and a second standard block, wherein the first adjoining block and the second adjoining block are located at the two ends of the top-sealing block, and the first standard block and the second standard block are located at the two ends of the bottom-sealing block. The first adjoining block is connected with the first standard block, and the second adjoining block is connected with the second standard block. Steel strand hole passages are formed in the existing first adjoining block and first standard block, steel strands are arranged in the steel strand hole passages, and steel strand outlets are formed in the inner sides of the first adjoining block and the first standard block. The second adjoining blockand the second standard block are also treated in the same way. The reinforcing method comprises the steps that (1) the lining segment is prefabricated according to the borne load of a tunnel structure; (2) the stress condition of the lining segment is judged, and the reinforcing method of the lining segment is determined; and (3) the lining segment is reinforced. According to the shield tunnel lining segment and the reinforcing method, the overall rigidity and the deformation harmony of the tunnel structure are improved, and tunnel operation safety can be ensured.