The invention discloses an insulating layer material for a core of a field cable, and relates to the technical field of materials for cables. The insulating layer material for the core of the field cable is made from the following raw materials in parts by weight: 30-40 parts of polytetrafluoroethylene, 15-20 parts of rubber powder, 10-15 parts of polyoxyethylene, 10-15 parts of disproportionated rosin, 8-12 parts of volcanic ash, 6-10 parts of melamine formaldehyde resin, 5-8 parts of sepiolite powder, 5-8 parts of straw dry powder, 4-6 parts of ceramic fine powder, 4-6 parts of stearic acid, 3-5 parts of carbomer resin, 3-5 parts of carnauba wax, 2-3 parts of nano rubber powder, 2-3 parts of urea, 1-2 parts of sulfated castor oil and 1-2 parts of nano aluminum powder. The insulating layer material provided by the invention can be directly used for wrapping the core, plays isolation and protection roles, is high in insulativity, has excellent flaming resistance, abrasion resistance, corrosion resistance and ageing resistance, and is long in service life and high in safety.