The invention relates to an irradiation crosslinking halogen-free high flame-retardant cable material and a preparation method thereof. The cable materials comprise the following compositions: 45-90 parts of basic resin, 10-55 parts of functional polyolefine resin, 45-125 parts of carbonate hydroxide flame retardant, 30-50 parts of charing agent, 30-50 parts of flame-retardant lubricant, 0.3-3 parts of methyl silicone rubber shell forming agent, 0.5-2 parts of silane surface modifier, 2-5 parts of crosslinking sensitizing agent, 0.2-2 parts of antioxidant, 1-4 parts of lubricant and 0.1-1.0 parts of initiator. The preparation method of the cable material comprises the following steps of: stirring the carbonate hydroxide flame retardant, the charing agent and the flame-retardant lubricant at a high speed for 2 min; and then adding the shell forming agent and continuously stirring at a high speed until the temperature rises to above 100 DEG C, coating the surface of the mixture with the shell forming agent; adding silane coupling agent and stirring for 5-8 min, and carrying out secondary surface treatment; adding initiator-alcohol solution, and discharging after mixing; extruding and pelletizing; finally drying and cooling to obtain the finished cable material product. The flame retardant performance of the product is obviously enhanced, and the product has good shell forming performance in conbustion without droplets.