The invention provides a three-axis automatic planing and sawing combination machine. The three-axis automatic planing and sawing combination machine comprises a conveying unit, a planing unit, a cutting unit, a lateral adjusting unit and a polishing unit. The lateral adjusting unit is arranged on the outer side face of a conveying path. The cutting unit comprises at least two saw blade sets, a conversion support capable of switching the two saw blade sets, and a saw blade driving mechanism. The saw blade sets are connected with the corresponding conversion supports. Each saw blade set comprises a plurality of saw blades and a saw blade rotating shaft used for connecting the saw blades in series. The saw blades are evenly distributed in the direction parallel to the long axis of each saw blade rotating shaft. The long axis of each saw blade rotating shaft is perpendicular to the front-back direction. The three-axis automatic planing and sawing combination machine can process panels of different widths. Due to arrangement of the cutting unit with the saw blade sets capable of being switched, the cutting distances of the saw blade sets can be switched quickly, there is no need to dismount original saw blade sets and mount new saw blade sets, equipment universality is enhanced, the planing, cutting and polishing technologies of the panels are achieved on one piece of equipment, space usage is small, production efficiency is high, and production cost can be better reduced.