The utility model discloses a strengthening device of a special-shaped wall corner of an aluminum alloy formwork. The strengthening device comprises the special-shaped wall corner and the aluminum alloy formwork used for manufacturing the special-shaped wall corner. A special-shaped back ridge for fixing the aluminum alloy formwork is arranged on the outer side of the aluminum alloy formwork and is a continuous transition integral back ridge, and the head end of the back ridge is perpendicular to the tail end of the back ridge. The integral special-shaped back ridge is designed according to different shapes of wall corners and is strengthened on the aluminum alloy formwork of the wall corner, and due to the fact that the special-shaped back ridge is in continuous transition on the aluminum alloy formwork, a strengthening weak point cannot be produced at the wall corner. When wall column concrete is poured, the mortar leakage at the wall corner formwork can be effectively avoided, and the quality and appearance of a formed wall column are guaranteed.