The paper proposes an iteration method of correction function superposition for initial estimate in the form of hyperbolic-trigonometric series by two coordinates, which as they are superimposed, mutually compensate the misclosures they generate in boundary conditions. The misclosures decrease as the number of iterations grows and a solution can be obtained with any degree of accuracy. Numerical results of calculating deflections and bending moments of a Kirchhoff cantilever plate under uniform loading are presented. Comparison with the Rcissner theory is given.