NOVELTY - Preparing thermal insulating solar battery backboard comprises using substrate resin, thermal conductive filler, UV absorbent, UV shielding agent and light stabilizer, adding above mentioned components in a high speed mixer to mix uniformly and stirring, adding the mixed granules in a dual-screw extruder and extruding and granulating to obtain the particle, drying the prepared particle, adding into a single-screw casting machine and flow extending film to a certain thickness, where the UV absorbent is UV-327, UV-329, UV-9, UV-P, and/or XH-622LD.    USE - The method is useful for preparing thermal insulating solar battery backboard (claimed).    ADVANTAGE - The method uses nylon, and polyester polymer as resin substrate body to replace the traditional fluorine material, thus reducing the cost, avoids the fluorine material in the processing process of the hydrogen fluoride. The backboard has thermal co-efficiency of 10W/(m.K) and resistivity of less than 1016 Omega .cm, and improves the power generation efficiency.    DETAILED DESCRIPTION - Preparing thermal insulating solar battery backboard comprises using 100 pts. wt. substrate resin, 5-10 pts. wt. thermal conductive filler, 0.1-1 pt. wt. UV absorbent, 5-10 pts. wt. UV shielding agent, and 0.5-1 pt. wt. light stabilizer, where the substrate resin is nylon 6, nylon 1010, nylon 1212 or polyethylene terephthalate, the thermal conductivity of nylon 6, nylon 1010 and nylon 1212 is 0.18-0.29W/(m.k), the thermal conductive filler is nano magnesium silicon nitride, nano silicon carbide, nano aluminum oxide, nano-boron nitride, high sphericity aluminum oxide and/or nano silicon nitride, the thermal conductive filler silane treatment comprises mixing silane coupling agent (silane dosage is 2-5% of total mass of the mixture) and ethanol aqueous solution (water:ethanol:silane is 8:72:20 mass ratio of the alumina), adding thermal conductive filler, stirring for 4-5 hours, ultrasonically dispersing for 2 hours, filtering, and drying, where the UV absorbent is UV-327, UV-329, UV-9, UV-P, and/or XH-622LD; the UV shielding agent is nano-titanium dioxide, zinc oxide, calcium carbonate or talc powder; the light stabilizer is hindered amine derivative, comprising light stabilizer 622, light stabilizer 770, light stabilizer 944, light stabilizer 783, light stabilizer 791, light stabilizer 3853, light stabilizer 292 or light stabilizer 123, adding above mentioned each components in a high speed mixer to mix uniformly and stirring at a speed of 200-500 revolutions/minute, adding the mixed granules in a dual-screw extruder and extruding and granulating to obtain the particle, where the extruder temperature is 210-280 degrees C, placing the prepared particle at 80 degrees C and drying, then adding into a single-screw casting machine and flow extending film to a certain thickness at 200-250 mu m, where the casting machine temperature is 210-280 degrees C.