Halogen-free and flame-retardant polycarbonate composition and preparation method thereof

The invention discloses halogen-free and flame-retardant polycarbonate composition. The composition is prepared from PC resin, PET resin, a compatilizer, a toughening agent, a halogen-free flame retardant, a synergistic flame retardant, an antioxidant and other aids, wherein the halogen-free flame retardant is at least one of a nitrogen-containing flame retardant, phosphorus-containing flame retardant and a metal organic sulfonate flame retardant; the synergistic flame retardant is a flaky silicate compound with the average grain size of 0.5-100 mu m. The halogen-free flame retardant with highflame retardance efficiency is used, and use of a flame retardant containing halogen is avoided; besides, the flame retardance performance of a PC/PET alloy is improved through combined use of the halogen-free flame retardant and the synergistic flame retardant; the halogen-free flame retardant can improve the flowability of the composition to a higher extent, has fewer influences on the mechanical property of the compos