Based on the basic principle of frequency response analysis method and the equivalent circuit model of transformer, aiming at the power transformer winding and mechanical structure deformation fault that is easy to be occurred in the practical engineering, a fault simulator is proposed which can be used for teaching and explaining about winding deformation frequency response method. Also can be used for testing the function of transformer wingding deformation frequency response tester is good or bad at the scene. According to the principle, all kinds of frequency responses caused by different transformer winding deformations is analyzed, and a quickly and simply way to identify the problem of transformer winding deformation is proposed in this paper. The results show that the proposed fault simulator is helpful to do winding deformation frequency response tester self-checking, and the proposed fault simulator is also useful for teaching and learning.