In order to optimize the structure configuration of the truss type legs of the self-elevating platform,the parametric modeling method and GeniE software of SESAM were adopted to evaluate the performance and strength of different leg configurations. Towing and survival conditions were analyzed in the study process. Series of leg bay heights were chosen for strength analysis under towing condition. Different leg configurations with chord spaces and bay heights under survival condition were chosen to calculate the anti-overturning capacity,maximum reaction of support,locking force and the UC values of leg components. Considering the leg weight,the optimal decision for the leg configuration was given according to the principle satisfying the optimized strength and economy. A certain jack-up unit leg design was finished rapidly by this method. The study result indicates that the present method is effective for leg configuration selection and optimization in the preliminary design stage.