Stable supporting device for trench excavation

The utility model discloses a groove excavation stable supporting device which comprises two supporting plates which are symmetrically arranged, the centers of the tops of the supporting plates are fixedly connected with connecting plates, an adjusting assembly is arranged between the two connecting plates, the two ends of the bottom wall of each supporting plate are symmetrically and fixedly connected with first fixing inserting rods, and the two ends of the bottom wall of each supporting plate are fixedly connected with second fixing inserting rods. An expansion plate is arranged in an inner cavity of the supporting plate, second fixing insertion rods consistent with the first fixing insertion rods in specification are arranged on the bottom wall of the expansion plate at equal intervals and fixedly connected with the bottom wall of the expansion plate, a through groove is formed in the bottom wall of the supporting plate, and the forming specification of the through groove is matched with the specification