In view of the good performance in pattern recognition using Kernel Fisher Discriminant Analysis（KFDA） method

this paper presented a fault diagnosis model of power transformer based on KFDA.The model extracted a feature to distinguish between discharge faults and hot faults first

and then used the KFDA classifier to distinguish in discharge faults or hot faults.To choose parameters of the model

this paper adopted the method of cross validation based on grid search

avoiding the arbitrary and capricious behavior.Practical analysis indicates that this model has advantages of short training time and no part teeny problem.Compared with three rations method of IEC and the improved three rations method

this model has considerable effectiveness of faults identification.