The invention relates to the field of application of optical film and specifically relates to a polyester reflective membrane for printing and a preparation method thereof. In order to solve a problem of limit service life of an existing reflective membrane for printing, the invention provides a polyester reflective membrane for printing. The reflective membrane comprises a polyester base membrane; an upper surface of the polyester base membrane is bonded with a high-molecular material, and a lower surface of the polyester base membrane is bonded with a transparent resin layer; glass beads are implanted into the transparent resin layer, and an implanting depth is 1/2-2/3 of a diameter of the glass bead; a focusing layer under the glass beads covers 1/3-1/2 depth of the glass beads; a reflecting layer is under the focusing layer; and a pressure sensitive adhesive layer and an anti-sticking layer are under the reflecting layer successively. The polyester reflective membrane for printing provided by the invention has high light reflection rate, good reflection effect, good weatherability and a long usage life. The invention also provides the preparation method of the polyester reflective membrane for printing, and the method has simple production technology and is easy for operation.