The civil aircraft airworthiness regulation and design requirements are studied in this paper. The fuel system relative airworthiness regulation on the liquid protection，lightning protection，electrostatic protection，track can drain outflow system safety airworthiness regulation are provided in list. As the baseline of the aircraft components detail design, based on the analysis of track can drain hose placement in the aerofoil fuel，the design requirements critical parts are summarized as follows: the liquid protection，lightning protection，electrostatic protection. Comparing the results of various forms of liquid outflow, the paper can provide design reference to aircraft detail design.