The boundary estimation algorithm of fault-tolerance performance was researched.By introducing the characteristic parameters of control surface dilapidation,the relationship between the control surface dilapidation and the characteristic polynomial of the control system was established.Based on the UAV flight quality,the boundary estimation problem of fault-tolerance performance was converted into a generalized stability problem of interval polynomials.Then,one class of stability problem of generalized stable region was solved by using Soh polynomial lemma.And the other class is transformed into a stability problem of interval polynomials,which can be analyzed by the Hurwitz stability criterion.Finally,a specific example was adopted to prove the feasibility of the method.