The invention discloses high-temperature resistant nylon and a nylon composite material with good fracture toughness. The high-temperature resistant nylon is prepared from 100 parts of aromatic dicarboxylic acid, 100 to 102 parts of aliphatic diamine, 2 to 4 parts of end capping agent and 1 to 2 parts of phosphorus-containing catalyst; the aromatic dicarboxylic acid consists of 80 to 95 percent of terephthalic acid and 5 to 20 percent of naphthalic acid; and the nylon composite material is prepared from 70 to 85 parts of high-temperature resistant nylon, 15 to 25 parts of ethylene-octene copolymer and 0.5 to 13 parts of aid. By optimizing the ratio of the terephthalic acid to the naphthalic acid in the nylon synthesis process and optimizing the formula content of an elastomer in the nylonmodification process, the modified nylon material with high initial impact failure energy (namely J criticality) is prepared, and the long-term working characteristics and the service life of the material can be effectively kept.