Abstract: The wail-beam is replaced by the transform beam whose rigidity is rigidity of the wall-beam and material the same as the wall to turn the wall and beam into homogeneous elasticity body. stress on the transform beam is calculated by the formulas in elasticity, then it is regarded as load with the wall actes upon beam. In this paper, the method is called equal rigidity substitution, its result has reflected approximately stress distribution law on contact surface between the wall and beam by identification for theory formulas and finite element method.