The invention discloses a special extension platform for cutting a thick plate by cooperating with an IK-WEASEL cutting machine. The extension platform comprises a platform plate, a U-shaped fixing clamping tank, a sliding tank and a sliding block; the left side of the front end of the platform plate is provided with a rectangular installing groove, the fixing clamping tank is fixedly connected tothe rectangular installing groove of the platform plate, the bottom of the fixing clamping tank is provided with two screw holes, and a butterfly bolt is connected to each screw hole in a screwing mode; and the sliding tank is fixedly connected to the right end of the platform plate, a tank port of the sliding tank faces rightwards, the sliding block is slidably installed in the tank port of thesliding tank, and a supporting plate perpendicular to the sliding block is fixedly connected to the right side of the sliding block. The extension platform has the beneficial effects that the thick plate does not need to be supported with hands by a worker when the corners of the thick plate are cut with the IK-WEASEL cutting machine, the labor intensity of the worker is reduced, and the machiningprecision is guaranteed.