The invention discloses an insulating rod body material and a preparation method thereof. The insulating rod body material comprises, by weight, 36-52 parts of epoxy resin, 8-14 parts of polyether-ether-ketone, 5-9 parts of glass fiber, 2-4 parts of polyurethane fiber, 3-7 parts of flame retardant, 1-3 parts of initiator, 2-6 parts of inorganic filler, 3-5 parts of plasticizer, 2-4 parts of coupling agent, 1-3 parts of photostabilizer and 1-3 parts of lubricant. The insulating rod body material prepared by the method is high in insulativity, low in heat conductivity and high in mechanical strength, has excellent flame-retardant performance, and is high in size stability, less prone to deformation, good in wear-resistant performance and free of influence on normal use of an insulating rod caused by damage under action of weathering, irradiation and inevitable stress when in use.