In order to deeply understand the influence of winding deformation on the leakage inductance parameters of high-frequency transformers, a global sensitivity analysis method for analyzing leakage inductance parameters to different winding deformation types is proposed. Firstly, the second-order and third-order response surface models of the leakage inductance parameters of the high-frequency transformer are established through the response surface method and the central composite test design, and it is proved that the calculation accuracy of the third-order response surface model is higher than that of the second-order response surface model. The goodness index and the maximum error are 0.991% and 0.34%, respectively. Secondly, based on Sobol’s sensitivity analysis method and Monte Carlo sampling method, the sensitivity of leakage inductance parameters to different types of deformation is analyzed. The results show that Sobol’s sensitivity analysis method can quantitatively analyze the influence of winding deformation on leakage inductance parameters, and the leakage inductance parameter is most sensitive to the radial deformation of the primary winding, and the first-order sensitivity and total sensitivity are 0.6951 and 0.6963, respectively. The research in this paper can provide guidance and basis for the structural design of high-frequency transformers and the detection of winding deformation.