“This paper introduces the research progress in the field of transformer winding deformation detection. Relevant experts have established a sensing system composed of three-phase current sensors in parallel, and verified the feasibility of using coil injection excitation signals and measuring the current response signal at the high-voltage output terminal of the transformer to draw the winding frequency response curve and diagnose transformer winding deformation defects during operation. This provides an effective solution to solve the problem of power frequency interference.”