Embedded sleeve for mounting buried U-shaped bolt

The embedded sleeve for installing the buried U-shaped bolt comprises movable shells which are arranged in a bilateral symmetry mode, the movable shells on the two sides are spliced to form a U-shaped structure, positioning grooves matched with the U-shaped bolt are formed in the outer side faces of the symmetrical movable shells, compared with the mode that the U-shaped bolt penetrates through a sleeving hole, the positioning grooves are communicated with the outside, and the U-shaped bolt penetrates through the sleeving hole. The U-shaped bolts can be conveniently matched with the positioning grooves, meanwhile, when the positioning grooves are blocked by sundries, cleaning is convenient, a fixed shell is arranged between the two movable shells, one end of the inner side of the bottom of each movable shell is movably connected with the fixed shell, the movable shells can be unfolded or folded, the interval between the two movable shells is adjusted according to the U-shaped bolts of different sizes, and the