An anchoring apparatus that adapts to the longitudinal movement of a structure and installation method therefor. The anchoring apparatus that adapts to the longitudinal movement of a structure comprises a flared steel casing tube (1) and a cable guide pipe (8); a cable (6) is threaded through the inside of the cable guide pipe (8), the cable (6) being fixed to an end of the cable guide pipe (8) by means of a cable seal tube (7); the flared steel casing tube (1) is located within the cable guide pipe (8); the inner diameter of the flared steel casing tube (1) gradually lengthens along the direction leading away from the cable seal tube (7); the outer wall of the flared steel casing tube (1) is fixed to the inner wall of the cable guide pipe (8). The installation method for the anchoring apparatus that adapts to the longitudinal movement of a structure comprises the following steps: machining the flared steel casing tube (1) according to the designed horizontal curve; inserting the flared steel casing tube (1) into the cable guide pipe (8) and fixedly connecting same to the inner wall of the cable guide pipe (8), forming an integral body; threading the cable (6) through the inside of the cable guide pipe (8) and performing tensioning. The anchoring apparatus that adapts to the longitudinal movement of a structure increases the contact area of the outer wall of the cable (6) and the inner wall of the flared steel casing tube (1), preventing part of the cable (6) from being subjected to a concentrated cutting force, improving the safety of the anchoring system.