In this paper we propose an algorithm for the calculation of nonlinear control systems. The algorithm is based on the representation of processes in the form of an expansion in the base system theme functions, and uses the machine structural reforms, as well as mathematical programming methods. Algorithm method involves replacing each link management system matrix opera. General feature of the algorithm is the calculation procedure of equivalent matrix operators' nonlinear elements using iterative schemes. Equivalence criterion is the equality of output signals of the nonlinear element and its equivalent linear element defined matrix operator, when developing a specific input. Such an approach makes it possible to transfer the synthesis problem is a class of linear systems. By the example of electronic automatic control system we considered in detail calculation algorithm. Obtained results show limiting accuracy of the solution.