Based on common contaminants in the fuel tank of large civil aircraft, contaminants were classified, the sources were studied, and the effects on the function, performance, safety and economy of the aircraft were analyzed. For aircraft development and production stage, contaminant protection design requirements were put forward from the aspects of material selection, fuel tank design, fuel system and related aircraft systems design, and contaminant protection control requirements were put forward from each link and element in manufacturing. For aircraft operation stage, contaminant protection monitoring requirements were put forward for service and maintenance. Continuous monitoring and management of fuel tank contaminants during the life cycle of the aircraft will support efficient production and safe operation for aircraft.