The utility model relates to a special fixture used for precise distance measurement, wherein, a positioning plate is connected with a handle on the lower side through a hexagon socket head screw; the bottom of a vertical adjusting helix passes through the positioning plate downwards; a rustproof copper band is arranged on a contact position of the positioning plate and a steel scale; a gap used for clamping the steel scale is arranged between the rustproof copper band and the handle; a round hole plate is arranged on one side of the handle; and a round hole used for covering a point to be detected for being in place is arranged on the round hole plate. The fixture fixes one end of the steel scale on a monitoring point position and a copper core of a monitoring point is driven to be on the steel scale, thereby reading is convenient; the fixture is placed on a benchmark and standard tension is exerted on the other end of the steel scale; when a tension gauge reaches the standard tension, the vertical adjusting helix of the fixture is screwed up; and the steel scale is fixed and reading and recording are simultaneously performed on the front scale and the rear scale.