The present invention provides an actuarial modeling method based on the car body combination property index of support vector machine, belonging to auto structure optimization design field, including step 1, selecting parts as design object, and determining thickness of parts, material parameter as design variable; step 2, adopting testing design method to generate design matrix according to the design variable determined by step 1; step 3, processing finite element simulation testing design according to the design matrix, extracting structural performance index value to complete the establishment of the training sample; step 4, training sample by supporting vector machine method, establishing combination property index mathematic model; step 5, verifying the established combination property index mathematic model by checking index; step 6, establishing adaptive process after verifying the high precision combination property index mathematic model. The invention is fit for nonlinear response index mathematical modeling having multiple variables, high structural performance, having high precision of the model prediction, high efficiency of modeling, high feasibility of optimum design.