The invention discloses a full-automatic small strip splicing machine. The full-automatic small strip splicing machine comprises a machine frame, a transmission chain rail mechanism, an adjusting mechanism, a hot melt glue line gluing mechanism, a butt joint bonding mechanism, a sizing shearing mechanism, a guiding ruler, a glue line support, a tray and a plurality of stand columns, wherein the adjusting mechanism is arranged at the front end of the machine frame; the guiding ruler is arranged on one side of the adjusting mechanism; the transmission chain rail mechanism is arranged on the upper portion of the machine frame; the transmission chain rail mechanism comprises an upper transmission chain rail and a lower transmission chain rail; the hot melt glue line gluing mechanism is arranged between the upper transmission chain rail and the lower transmission chain rail; the butt joint bonding mechanism is arranged on the rear side of the hot melt glue line gluing mechanism; the glue line support is arranged on one side of the machine frame; the tray is arranged on the upper portion of the glue line support; the plurality of stand columns are arranged on the upper portion of the tray; and the sizing shearing mechanism is arranged on the rear side of the transmission chain rail mechanism. The machine is suitable for splicing single plate small strips from 20 mm to 300 mm, so thatthe technical gas that narrow strip single plates in the market cannot be sewn is filled, and the utilization of raw materials and left over materials are greatly improved.