The invention discloses an aircraft environmental-protection sealant. A base paste is composed of 100 parts of liquid polysulfide raw rubber, 20 to 50 parts of active nano calcium carbonate, 1 to 10 parts of light calcium carbonate, 1 to 10 parts of gas-phase silica, 0.5 to 5 parts of magnesium stearate, 10 parts of dioctyl terephthalate, and 0.1 to 3 parts of vinyltriethoxysilane; a vulcanized paste comprises the following components in parts by weight: 100 parts of manganese dioxide, 8 to 20 parts of dioctyl terephthalate, 0.1 to 10 parts of 1,3-biphenyl fluorene, 10 to 30 parts of carbon black, 1 to 10 parts of epoxy resin, and 0.1 to 3 parts of sulfur; and the weight ratio of the base paste to the vulcanized paste is 5 to 20:1. The aircraft environmental-protection sealant satisfies the environmental protection requirements of the European Union, does not use a phthalate plasticizer, and is harmless to the aircraft manufacturing and health of maintenance personnel. After adding anenvironmentally friendly plasticizer, the aviation kerosene-resistant performance is increased, the quality decrease condition of the sealant due to plasticizer migration and the degradation of sealant molecular chain is reduced, the probability of aircraft oil leakage caused by the decrease of sealant performance is reduced, and the sealant has broad market application prospect.