The invention provides a weather-resisting type lightweight light-shading-matte PA56/ASA (Polyamide 56/Acrylonitrile Styrene Acrylate copolymer) alloy material and a preparation method of the weather-resisting type lightweight light-shading-matte PA56/ASA alloy material. The weather-resisting type lightweight light-shading-matte PA56/ASA alloy material is prepared from the following components in percentage by weight: 30 weight percent to 70 weight percent of PA56 resin, 30 weight percent to 70 weight percent of ASA resin, 2 weight percent to 5 weight percent of a compatilizer, 2 weight percent to 10 weight percent of a toughening agent, 3 weight percent to 10 weight percent of a light-shading auxiliary agent, 0.2 weight percent to 0.5 weight percent of an antioxygen and 0.3 weight percent to 0.8 weight percent of a lubricant. According to the weather-resisting type lightweight light-shading-matte PA56/ASA alloy material provided by the invention, the novel resin PA56 with excellent performance and the weather-resisting type resin ASA are prepared into an alloy and the alloy has a natural matte surface and high toughness which is comparable with, even better than that of a common PA/ABS (Acrylonitrile Butadiene Styrene) alloy; meanwhile, the weather resistance is extremely improved; titanium dioxide is compounded with other dyestuffs with small relative density and better light-shading effect to obtain a material with relatively lower density, so that light weight of terminal application is realized; the weather-resisting type lightweight light-shading-matte PA56/ASA alloy material can be widely applied to outdoor lamp decoration parts, automobile internal lamp button parts and the like.