The utility model relates to a connecting and fixing structure for a corner of a line stone plaque. The connecting and fixing structure comprises a first stone plate, a second stone plate, a reinforcing pin plate and a corner fixing piece, the first stone plate is fixedly connected with a wall body structure, the first stone plate and the second stone plate are vertically spliced, and the opposite splicing surfaces of the first stone plate and the second stone plate are inclined surfaces; fixing grooves are formed in the splicing faces of the first stone plate and the second stone plate in the length direction, the two fixing grooves are perpendicularly arranged, and notches of the fixing grooves are opposite. The reinforcing pin plate is of a right-angle plate-shaped structure and is inserted, bonded and fixed in the fixing grooves of the first stone plate and the second stone plate. The corner fixing piece is in a right-angle shape and comprises a first fixing part and a second fixing part which are perpendicular to each other, and the first fixing part and the second fixing part are connected with the first stone plate and the second stone plate in an anchoring mode through back bolts respectively. According to the utility model, the connection rigidity of the corner stone is improved, the stress condition of the corner of the line stone is improved, and the safety and reliability of the structure are improved.