NOVELTY - A black polyester solar battery rear film comprises polyester slices and black polyester main materials in 4.0-19.0:1 (pts. wt.). The black polyester main materials comprise 45-98.3 wt.% polyester slices, 1-30 wt.% carbon black, 0.5-10 wt.% silicon dioxide, 0.1-10 wt.% organic dyes, and 0.1-5 wt.% ultraviolet absorber. The carbon black is subject to organized surface process, and the grain diameter is 100-1000 nm. The silicon dioxide is subject to organized surface process and the grain diameter is 10-100 nm.    USE - A black polyester solar battery rear film.    ADVANTAGE - The product has good light shielding property, insulating performance, and relative good aging resistance and barrier property.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing the black polyester solar battery rear film, comprising mixing 45-98.3 wt.% polyester slices, 1-30 wt.% carbon black, 0.5-10 wt.% silicone dioxide, 0.1-10 wt.% organic dyes, and 0.1-5 wt.% ultraviolet absorber into a material mixing machine, and mixing them sufficiently and making out black polyester main materials. According to 4.0-19.0:1 pts. wt., the polyester slices and black polyester main material are placed into the material mixing machine and mixed, and pre-crystallized for 3-6 hours at 60-100 degrees C inside a vacuum rotary drum. The pre-crystallized mixing material is dried for 2-6 hours at 12-170 degrees C. The dried material is conveyed into an extruding machine, melted, extruded, cast into sheets at 270-300 degrees C, and made into thick sheets. The thick sheet is pre-heated at 50-85 degrees C, entered into far infrared heating region at 110-50 degrees C, and stretched longitudinal with thread speed of 3-5 m/minute. The multiplying rate of the longitudinal stretching is 1.5-3.5. Pre-heating the longitudinally stretched film sheets is done at 90-135 degrees C. Transverse stretching is performed at 100-150oC. The multiplying rate of the transverse stretching is 1.5-3.8. The film sheets are shaped at 200-240 degrees C and rolled.