In this paper,the no-linear bending problem of rectangular thin plate with varying thickness subjected to any transverse load with simple supported edges is studied by the L.M.H.Navier method,and the general solution is obtained.When the plate bent with large defection,taking the deflection w and stress function as the unknown functions,the governing partial differential equations are derived by considering the equilibrium of a plate element.Expanding deflection w,stress function φ and q in the governing partial differential equations into double trigonometric series,reduces the problem to the solution of a set of algebraic equations,which can be done without mathematical difficulty.