Numerical control slot milling machine

The invention discloses a numerical control slot milling machine comprising a machine frame, a gas floating work table, a clamp mechanism, a first machining unit, a second machining unit, a third machining unit and a side leaning mechanism. The gas floating work table is provided with a gap with an adjustable size. The clamp mechanism can be movably arranged on the machine frame in the first direction. The first machining unit comprises a first cutter used for machining the upper surface of a to-be-machined part, and the first cutter can move in the second direction and the third direction. The second machining unit comprises a second cutter used for machining the side face of the to-be-machined part, and the second cutter can move in the second direction and the third direction. The third machining unit comprises third cutters used for machining the lower surface of the to-be-machined part, and the third cutters penetrate through the gap in the gas floating work table to machine the to-be-machined part. The