The invention discloses a transformer winding deformation detection system. The detection system comprises a signal input module, a signal collecting module, a data processing module, a signal correcting module and a detection module, wherein the signal input module is used for inputting detection signals to the primary side of a transformer, the signal collecting module is used for collecting response signals of the transformer, the data processing module is used for computing the response signals to obtain a corresponding short-circuit impedance percent, the signal correcting module is used for storing the response signals of the transformer and correcting the detection signals according to the response signals, and the detection module is used for detecting transformer winding deformation with the short-circuit impedance percent. The invention further discloses a detection method for the transformer winding deformation detection system. Defects in the prior art can be overcome by the system, and detection accuracy when transformer load frequently fluctuates in a wide range is improved.