The invention discloses a pipe thread sealant for tunnel construction. The pipe thread sealant is prepared from 30-40 parts of epoxy resin, 15-25 parts of PTMG (poly(tetramethylene ether) glycol polyols), 5-15 parts of TDI (2,4-toluene diisocynate), 5-10 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane, 1-5 parts of AIBN (azodiisobutyronitrile), 1-5 parts of PBMA (polybutyl methacrylate), 5-10 parts of styrene elastomers, 2-6 parts of poly(2,6-dimethyl-1,4-phenylene oxide), 5-10 parts of polyvinyl acetate, 5-15 parts of ceramic particles, 1-5 parts of silicon dioxide, 1-5 parts of an antioxidant and 1-3 parts of a tackifier. The pipe thread sealant is prepared from the epoxy resin as a main raw material and has good wettability, lubricity and waterproofness, all possible leakage paths ofa thread can be sufficiently filled with sealing grease, an elastoplastic polymer is formed by curing, a sealing layer is formed on the thread surface, so that the sealing part is free of holes and gaps, and meanwhile, the product has good heat resistance, cold resistance, high-pressure resistance and aging resistance.