Prism fixing device for steel tube arch bridge measurement

The utility model relates to a prism fixing device used for steel tube arch bridge measurement, and relates to the technical field of prism measurement, the prism fixing device used for steel tube arch bridge measurement comprises a fixing plate, a prism, a support, a measuring piece and a telescopic screw rod, and the center of the fixing plate is provided with a through accommodating opening; the prism is arranged in the accommodating opening, and the center of the prism coincides with the center of the fixing plate; the multiple supports are horizontally connected to the upper end face of the fixing plate, each support is provided with a measuring piece in the axis direction, and the multiple measuring pieces are used for positioning the center of a steel pipe when the fixing plate is erected in a steel pipe opening through the supports; the multiple telescopic screws are horizontally connected to the lower end face of the fixing plate and used for abutting against the inner wall of the steel pipe when the