The invention discloses a seamless laser film and a preparation method thereof. The seamless laser film is characterized by sequentially comprising the following structures in three layers from bottom to top: a PET (polyethylene terephthalate) film layer, a resin coating layer and an aluminum layer. The preparation method comprises the following procedures: molding the PET film layer; coating; mold-pressing; aluminizing; board-compounding and printing, wherein, the mold-pressing is performed for another time after the mold-pressing of the first time; and injectable tubes are added to pressing rolls, thereby controlling the temperature. By avoiding periodic plate seams of the laser film, the preparation method can reduce the loss of subsequent production and improve the production efficiency.