The invention discloses a special-shaped reinforcement cage which comprises a cylindrical reinforcement cage body and at least one expanding part. Each expanding part comprises at least three umbrella ribs arranged around the cylindrical reinforcement cage body, wherein the umbrella ribs can rotate between a first set position and a second set position. When the umbrella ribs are located in the first set position, the special-shaped reinforcement cage can be freely placed in a pile hole using the special-shaped reinforcement cage body. When the umbrella ribs are in the second set position, the distance between the end portions of the free ends of the umbrella ribs and the central axis of the cylindrical reinforcement cage body is 1.5-3.5 times of the radius of the cylindrical reinforcement cage body. The invention further discloses a construction method for a special-shaped uplift pile using the above special-shaped reinforcement cage. The above special-shaped reinforcement cage is located in the expanding parts. The special-shaped reinforcement cage is simple in structure and can be in sufficient and even contact with concrete of a pile body when serving as a reinforcement structure of the uplift pile, and therefore the manufactured uplift pile can bear large anti-buoyancy force.