The invention provides a method for determining tuning deviation of an ultrahigh-voltage filter of a convertor station. The method is characterized in that allowable reasonable deviation criterion of the filter is as follows: Deltaf0/f0=1/2DeltaC/C+1/2DeltaL/L, wherein Deltaf0/f0 is a turning point frequency change rate, Delta C/C is a change rate of capacitor parameters relative to a rated rate, Delta L/L is a change rate of electric reactor parameters relative to a rated value, Delta f0/f0 represents the deviation between practical turning point frequency which is allowable on design and a theoretical turning point frequency; as long as the practical turning frequency of the filter is regulated until deviation between the practical turning frequency and the theoretical turning point frequency corrected by a temperature is smaller than the calculated value of the Delta f0/f0, the filter turning is qualified. According to the allowable filter parameter deviation, the method is used for calculating allowable tuning deviation criterion of the filter through theoretical calculation, has inherent rationality and makes up the defects of a filter turning theory, and is proved to be convenient and practical according to the multi-time practical application.