NOVELTY - A low filling halogen-free intumescent flame retardant photovoltaic packaging material contains 100 mass parts photovoltaic packaging base material, 10-23 mass parts microencapsulated intumescent flame retardant, 2-15 mass parts coupling agent-treated inorganic nano-flame retardant, 0.1-10 mass parts peroxide cross-linking agent, 0.05-5 mass parts phenolic or phosphite antioxidant, 0.01-5 mass parts hindered amine light stabilizer, 0.01-2 mass parts UV absorber, and 0.01-3 mass parts thickener in which photovoltaic packaging base material is ethylene-vinyl acetate copolymer.    USE - A low filling halogen-free intumescent flame retardant photovoltaic packaging material (claimed).    ADVANTAGE - Low filling halogen-free intumescent flame retardant photovoltaic packaging material has heat resistance and low cost and is moisture-proof.    DETAILED DESCRIPTION - A low filling halogen-free intumescent flame retardant photovoltaic packaging material contains 100 mass parts photovoltaic packaging base material, 10-23 mass parts microencapsulated intumescent flame retardant, 2-15 mass parts coupling agent-treated inorganic nano-flame retardant, 0.1-10 mass parts peroxide cross-linking agent, 0.05-5 mass parts phenolic or phosphite antioxidant, 0.01-5 mass parts hindered amine light stabilizer, 0.01-2 mass parts UV absorber, and 0.01-3 mass parts thickener in which photovoltaic packaging base material is ethylene-vinyl acetate copolymer, metallocene catalyzed polyethylene, ethylene-octene copolymer, and/or ethylene-pentene copolymer, microencapsulated intumescent flame retardant is microencapsulated polyphosphate melamine borate, and coupling agent-treated inorganic nano-flame retardant is nano-aluminum hydroxide, nano-magnesium hydroxide, nano-silicon dioxide, nano-zinc oxide, and/or nano-titanium dioxide. An INDEPENDENT CLAIM is included for preparation of low filling halogen-free intumescent flame retardant photovoltaic packaging material which involves ball milling phosphate compound:melamine compound:boric acid with molar ratio of 0.05-1.5:1:1-1.5 for 10-20 minutes to obtain melamine-phosphate-boric acid (MPB) mixed material in which phosphate compound is ammonium polyphosphate, phosphoric acid, and/or bisphenol phosphate, melamine compound is melamine and/or melamine salt, reacting at 300-500 degrees C for 1-3 hours to obtain MPB, milling for 15-30 minutes, adding water:ethanol solution with volume ratio of 1:1 to obtain 18-25 wt.% MPB solution, adding MPB solution:cetyl trimethylammonium bromide with mass ratio of 1:15-25, stirring for 0.5-1 hours, adding melamine resin to obtain 1-5 wt.% MPB solution, heating in water bath at 70-90 degrees C for 1.5-3 hours, cooling, filtering, washing with deionized water for 3-5 times, drying at 70-90 degrees C for 18-22 hours to obtain MPB, adding 0.5-1.5 wt.% coupling agent in anhydrous ethanol, adding nano-flame retardant, ultrasonically mixing for 1-3 hours with oscillation frequency of 100-140 beats/minute, drying at 50-90 degrees C for 10-34 hours to obtain coupling agent-treated inorganic nano-flame retardant, standing, placing peroxide cross-linking agent, phenolic or phosphate antioxidant, hindered amine light stabilizer, UV absorber, and thickener in water bath at 50-70 degrees C, stirring for 10-30 minutes to obtain mixed additive, standing, adding photovoltaic packaging base material in mixer, adding 1/3-1/5 mixed additive, stirring for 2-2 minutes, adding remaining mixed additive, continuously stirring for 1-2 minutes, adding MPB and coupling agent-treated inorganic nano-flame retardant, stirring for 3-5 minutes, extruding in extruder at 80-100 degrees C, casting into film, cooling, cutting, and rolling.