The utility model discloses an outer burr cutting device for a high-frequency longitudinal welded pipe production line. The device comprises a scraper which is oblique backwards, wherein a cutting and pressing mechanism is arranged in front of the scraper and comprises a supporting frame fixed on a welding machine frame on the production line, a guide cylinder is vertically arranged on the supporting frame, a guide rod is inserted in the guide cylinder, the upper end of the guide rod is connected with the retractable end of a cylinder which is fixed on the supporting frame, the guide rod is connected with the guide cylinder through a guide key which is fixed on the guide cylinder, a cutting and pressing roller perpendicular to the guide rod is installed at the lower end of the guide rod, at least one protruding cutting and pressing tool is arranged on the outer surface of the cutting and pressing roller and presses a welding seam horizontally, and the cutting and pressing tools are perpendicular to the welding seam and parallel to the axis of the cutting and pressing roller. Outer burrs cut off by the device can be removed and collected conveniently, and no potential safety hazard exists.