We expand the earlier invented method of massive Feynman diagrams calculation, namely, the differential equations method, to N-point diagrams. We obtain a simple algorithm which allows us to reduce the vertex-type diagram to the propagator-type diagrams, the box-type diagram to the vertex-type diagrams and, in general, the N-point diagram to the (N-1)-point diagrams. We show that this method provides a simple procedure of evaluating the result without D-space integrals (for the dimensional regularization) calculation. 15 refs. (author).