V_MU is the minimum speed at and above which the aircraft can safely lift off the ground and continue the takeoff, expressed in terms of calibrated airspeed, and is the basis for formulating other takeoff speeds of the aircraft. As a typical high risk flight test subject, the V_MU test is a key concern of the Administrator during airworthiness certification. Based on the takeoff speeds section of CCAR25.107, combined with relevant Advisory Circular, this paper analyzes the requirements of the airworthiness clause of the V_MU, analyzes the characteristics of the V_MU, gives the airworthiness certification concerns, systematically analyzes the risk and the risk reduction measure of the V_MU for civil aircraft. It can provide reference for verifying the airworthiness compliance of the V_MU section of civil aircraft.