Cracking　angle　is　between　fixed　angle　and　rotating　angle,　which　is　the　real　direction　angle　of　cracks.　Based　on　the　stress　equilibrium,　strain　compatibility,　constitutive　laws　of　steel　bars　and　concrete,　Poisson　effect　coefficients,　a　reinforced　concrete　cracking　angle　softened　membrane　model　was　proposed,　which　included　the　interaction　between　tensile　strains　and　compressive　strains.　A　calculation　method　from　stresses　to　strains　was　provided　in　this　paper.　Compared　with　the　traditional　calculation　method　from　strains　to　stresses,　the　proposed　calculation　method　is　simpler,　and　trail　and　error　procedure　can　be　avoided.　The　calculation　results　coincide　with　the　test　data　of　eight　reinforced　concrete　panels,　which　verifies　the　correctness　of　the　proposed　reinforced　concrete　cracking　angle　softened　membrane　model　and　the　related　calculation　method.