The invention discloses a high CTI high impact flame retardant reinforced PA6/PBT material and a preparation method thereof, in particular relates to the technical field of high molecular materials, wherein the preparation raw material comprises the following components in parts by mass: 10-45 parts of PA6, 10-45 parts of PBT, 10-30 parts of glass fiber, 10-20 parts of composite flame retardant master batch, 1-5 parts of compatible toughening agent, 0.2-1.5 part of antioxidant, 0.2-2.0 parts of lubricant; wherein PA6 is polycaprolactam; the PBT is polybutylene terephthalate; the composite flame retardant master batch is a mixture of an iron red phosphorus master batch 40, a melamine polyphosphate 30 and a high CTI auxiliary agent 20; the compatible toughening agent is maleic anhydride grafted ethylene octene copolymer. The PA6 and PBT are compounded to prepare alloy, so as to effectively combine the performance advantages of the two, so that that advantages can be complemented and thedimensional stability can be improved, at that same time, the composite flame-retardant master batch is added to improve the comprehensive mechanical property of the material and greatly improve the impact resistance and CTI value.