The quantitative assessment of flight risk under condition of ice formation on wings can provide reference indicators for aircraft icing airworthiness verification. A quantitative risk assessment method of the extreme value theory combined with the Copular model for wings under condition of ice formation is proposed. Monte Carlo simulation experiments being made based on the complex dynamics model of pilotaircraftenvironment, the extreme values of key flight parameters (airspeed, roll angle and AOA) are extracted. The goodness of fit test is made by using the identified parameters. Joe Copula model can more accurately describe the joint distribution of threedimensional extreme value parameters in verification. The flight risk probability is calculated through the established risk probability criterion. The analysis shows that icing risk events are often to the accompaniment of varying degrees of overrun and coupled effects of key flight safety parameters. The proposed method can provide a theoretical reference for the quantitative assessment and predictive control of flight risk under icing conditions.