Provided is an automatic tile blank bar cutter. The automatic tile blank bar cutter comprises a rack, wherein conveying-in guide rollers used for conveying clay bars in are installed on one side of the rack, conveying-out guide rollers used for conveying the clay bars out are installed on the other side of the rack, a drive roller is installed between the conveying-in guide rollers and the conveying-out guide rollers, a bottom blade is installed on the outer circle of the driver roller, a bar cutting cutter shaft is installed above the drive roller, and is driven by the bar cutting cutter shaft to rotate, and a bar cutting blade is installed on the bar cutting cutter shaft. The automatic tile blank bar cutter is designed by making use of the advantages of an extruder through a bold conception. The automatic tile blank bar cutter does not use power, blank cutting is accomplished through thrust of the clay bars of the extruder, and the automatic tile blank bar cutter is an ideal product which is economical and environmentally friendly, saving energy, and being practical and reliable.