The invention discloses a lightweight polycarbonate material, made from, by weight, 140-160 parts of a carbonate monomer, 2-3 parts of pyromellitic dianhydride, 1-2 parts of ammonium molybdate, 6-8 parts of oxidized polyethylene wax, 10-12 parts of polyether glycol, 0.8-1 part of ethylene bis-stearamide, 1-2 parts of calcium acetylacetonate, 10-13 parts of lightweight filler, 1-2 parts of trimethylolpropane, 0.4-1 part of 2-mercaptobenzimidazole, 3-5 parts of N-methylpyrrolidone, 0.8-1 part of sorbitan monooleate, 0.1-0.2 part of stannous sulfide, and 16-20 parts of anhydrous toluene. The lightweight filler is organically modified and is subjected to mixed esterification with acid-doped polyester, the dispersity of the lightweight filler in a polyester matrix is effectively improved, the compatibility of the lightweight filler with other materials is improved, the stability strength of a finished product is improved, and the mechanical properties of the finished product are enhanced.