The invention discloses a halogen-free flame-retardant polycarbonate (PC) material and a preparation method thereof. The polycarbonate, a microencapsulated red phosphorus flame retardant, a carrier resin, a flexibilizer, a synergetic flame retardant, a lubricating agent and a stabilizing agent are mixed, and extruded by a double-screw extruder so as to prepare the product, wherein the microencapsulated red phosphorus flame retardant can be replaced by master batch consisting of microencapsulated red phosphorus powder and PC or the carrier resin; and the master batch can be a red phosphorus flame retardant master batch RPM240 or RPM250 product which is produced in Free Blue Star (Chengdu) New Material Co., Ltd. and takes the PC as a carrier. The halogen-free flame-retardant PC material hasthe advantages of high flame retardance, higher heat resistance, and flame retardance of UL94V-0 (0.38mm), and can be applied to the production of electronic and electrical internal insulation films.