Abstract: he differential equation of bending deformation of physically nonlinear material beam is established,and the analytical solution of bending deformation of physically nonlinear material beam with statically indeterminate support is obtained. The results show that when the statically indeterminate beam of physical nonlinear material is bent,there may be many different bending deformation differential equations in the same beam section due to the power of strain in the stressstrain constitutive relation. However,this factor has not been taken into account in the study of bending deformation of beams made of physical nonlinear materials in the relevant literature,so the wrong results are obtained.