The method of modeling and mesh generation about 3-unit tooth/restoration complex were established. The three-dimensional finite element models were subjected to four types of occlusal load applied to pontic element to evaluate 3 fiber framework designs and 3 cavities preparation configurations. By comparing the difference of stress distribution, following conclusions were obtained: the principal stress under buccal-lingual cusp load in traditional fiber framework pontic increased by 6.22% compared to that in pure composite resin pontic; optimized fiber framework obviously reduced stress level under any load; modified cavities exhibited better stress transfer and decreased share stress at adhesive interface than traditional cavities.