The oxygen concentration in the fuel tank of civil aircraft was prescribed in the airworthiness regulation. More attention shall be paid to the fuel tank Nitrogen-Enriched Gas (NEA) distribution scheme design to meet the airworthiness requirement. Based on fuel tank washing inert theory, the type selection design method for fuel tank NEA distribution scheme was introduced in this paper. The type selection design method was presented on a certain type aircraft fuel tank in this paper. The NEA flow could be calculated by using single-compartment fuel tank numerical model with fuel tank volume and inerting time. In order to simplify the tube placement, NEA distribution scheme could be designed by using multi-compartment fuel tank numerical model. Numerical simulation method could estimate the performance of NEA distribution scheme quickly, which is very useful for the type selection design phase while many inputs haven爷t been determined.