The drainage of civil aircraft from a high-set leak source is a special scenario drainage situation. The conventional drainage design and verification method ofcivil aircraft cannot meet the design requirements of the special scenario drainage situation. This article summarizes the drainage design and verification process for a special scenario drainage situation of civil aircraft, analyzes the drainage design requirements of high-set leak source, selects the drainage diversion groove which satisfies the directional drainage function as the high-set leak source drainage device, sorts out the conventional and specific drainage design requirements for high-set leak source. The design scheme of the drainage diversion groove and the design confirmation method were demonstrated, and the drainage test verification method of the drainage diversion groove was studied. Thereby the design and verification method of high-set leak source drainage of civil aircraft was fully demonstrated, which has certain guiding significance for the design and verification of drainage in special scenarios.