A new method for a stress–strain analysis of layered composites, named the finite-layer method, is proposed, which is based on the consideration of each particular layer as a constituent of the entire laminate. This method serves as a unified approach to the development of new algorithms for computing stresses in composite layers, interlaminar contact stresses, large deflections, and critical buckling loads of thin-walled laminated structures with delaminations. The calculation of a laminated structure is reduced to solving a boundary-value problem for a system of first-order ordinary differential equations. The number of equations depends on the number of layers in the composite. The resolving system of differential equations is a stiff system. The stable numerical method of discrete orthogonalization is used for solving the boundary value problem. Part 1 is dedicated to the application of the proposed method to a linear analysis of free-edge stresses in composite laminates, to a study of the deformation of composite plates with delaminations and bending of composite beams with patches, and to calculations of adhesive joints.