Aiming at the design requirements of easy separation and light mass for the sabot of integrated launch projectile, an optimization design model was obtained by combining the aerodynamic calculation model by the genetic algorithm, in which the aerodynamic calculation model was established on the basis of the theory of shock and expansion wave through building the parameterized structure model for windward nest. And the discard acceleration and sabot′s mass were used as the indicators to build performance function. Taking the sabot design of armor piercing fin stabilized discarding sabot of medium caliber as an example, the proposed optimization model was used for the optimum structural design of the windward nest, and the simulation model of sabot discard based on dynamic grid technique was adopted to verify the optimality. Simulation results show that the proposed optimization design model can obtain the optimal wind′s eye of the sabot; in view of the existing armor piercing fin stabilized discarding sabot of medium caliber, the sabot structure can be further optimized to improve its rapidity.