The invention discloses an inner spiral groove milling machine which comprises a machine body, wherein, one end of the machine body is provided with a workholding fixture, and the other end thereof is provided with a push-and-pull device; the push-and-pull device is connected with a cutter bar through moving and rotating a converter; the end part of the cutter bar is connected with a tool holder;the surface of the tool holder is provided with a spiral limit groove; the machine body is fixedly connected with a limit frame; the limit frame is connected with a limit mechanism extending into thespiral limit groove; and the limit mechanism is matched with the spiral limit groove to enable the cutter bar to rotate in the moving process. The machine has the advantages of simple structure, low manufacturing cost and high processing efficiency.