The utility model relates to a deflectable cutting device for a coal mining machine, mainly solving the technical problem of low production efficiency; the technical proposal thereof is as follows: the device is provided with a transition frame; a tail end of the transition frame is hinged with a machine body; a side A of a head end of the transition frame is hinged with a rocker assembly; a side B of the head end of the transition frame is provided with an oil cylinder assembly; an end of the oil cylinder assembly is hinged with the transition frame, the other one end is hinged with the rocker assembly; the deflectable cutting device for the coal mining machine is suitable for high-power coal mining machines for thin and thinner coal beds under a complex geological condition.