The structural forms of cylindrical stiffened composite panels are widely used in the aerospace field. The weight and pressure bearing capacity are determined by the structure layout. Aiming at layout optimization of cylindrical stiffened composite panel, discretization method is applied to the optimization. Stringers’ distance and panel’s length are dispersed into several values and typical sections are chosen for the stringer. To optimize ply thickness of 0°、±45°、90° and section sizing of stringer ,structural weight is chosen as objective function and critical buckling load is constraint. The 700 results indicate that t-section stringer is most favorable in structural lightweight design. the design curves are also obtained.