Panel-type radiator plays an important role in the heat dissipation of oil-immersed transformers. To study the influence of structural parameters of panel-type radiator on its heat dissipation performance,the multi-variable design matrix is designed by using the Box-Behnken design (BBD) method. These three key parameters (the height of the panel-type radiator, the number of weld passes,and the difference of the weld pass height) are used as independent variables,and the heat dissipation and flow resistance are the response values. STAR-CCM+ is used for numerical simulation of the model and corresponding response results are obtained. Based on the variance analysis of heat dissipation and flow resistance of the model,a quadratic regression model is obtained to analyze the interaction effects of the height of the radiator and the number of passes on heat dissipation and flow resistance. Finally,the desirability approach is used to optimize the parameters of the dispersion and determine the optimal structural parameters. The results show that the predicted values and simulation results are distributed around the regression line. The error between the predicted and simulation results is within 10%,which meets the requirements of engineering design. The increase in the height of panel-type radiator and the number of weld passes leads to an increase in heat dissipation and flow resistance,but the sensitivity of heat dissipation and flow resistance to panel-type radiator height is higher than the number of weld passes. The panel-type radiator has the best heat dissipation performance when the values of the panel-type height, the number of weld passes,and the difference of weld passes height are 2 483 mm,6,and 60 mm respectively.