An environment-friendly brake block with a double-layer composite structure comprises a steel backing and a brake block body, wherein the brake block body comprises a thermal-insulation bonding layer and a frictional layer, wherein the thermal-insulation bonding layer is prepared from the following components in parts by weight: PROMAXON (registered trademark)-D calcium silicate, SiC organosilicone modified phenolic resin, magnesium oxide, nanometer zinc oxide, nanometer aluminum oxide, isopropanol, zircon powder, multiwalled carbon nanotube, lauryl sodium sulfate, polyacrylonitrile preoxidized fiber and nitrile-butadiene rubber; the frictional layer is prepared form the following components in parts by weight: aramid fiber, polyacrylonitrile preoxidized fiber, alkali-free expanded glass fiber, ceramic fiber, calcium sulfate whisker, potassium titanate whisker, graphene, cashew nut oil frictional powder, flake aluminum powder, tantalum carbide, zirconium silicate, nanometer zinc oxide, molybdenum trioxide and SiC organosilicone modified phenolic resin. The brake block has the characteristics of environment friendliness, good high-temperature heat fade resisting property, favorable wear-resisting property, stable friction coefficient, long service life and the like.