The invention relates to a method for continuously producing a heat-insulated corrugated conduit pipe (1) comprising at least one inner pipe (2). A corrugated outer casing of the conduit pipe is first produced using an extruder (27) and a corrugator (28), and the inner pipe arranged in a film tube together with a foam-forming starting material is guided into the corrugator, in which the previously corrugated outer casing of the conduit pipe is filled with the heat-insulating foam. The device (10) provided for carrying out the method has a protective pipe (26), by means of which the inner pipe surrounded by the film tube can be guided into the corrugator in a separate manner from the extrusion and corrugation process of the outer casing.