Abstract: A cutting angle adjustment device for a stone cutter includes a rectangular water sink, an inverse L-shaped support arm anchored to a lateral side of the sink, a stone cutter adjustably connected to the support arm through a coupling assembly, a pair of guide rods parallel disposed to a pair of rack on front and rear ends of the sink, a platform having two alignments of rotors symmetrically arranged and slidably engaging with the inner sides of the pair of guide rods, a vertical cutting slit and a slant cutting slit parallel formed in the upper surface thereof. Thereby, a saw blade has been adjusted vertically and/or slantly relative to the top of the platform to conduct a vertical or slant cutting and a shallow or deep cutting of the working pieces.