[en] The iterative computer system, aimed at automatic control of engineering industry designer's position, is developed to raise the reliability as well as to shorten the period of designing ion-optical systems (IOS) of direct action accelerators. It is realized as a system of programs, providing main functions, which are the following: a calculational model, describing charged particle (electrons or ions) strip beam transport in plane fields, taking into account strengths of Coulomb repulsion and velocity spread of particles in transverse direction; data input and processing; computation of electromagnetic accelerating and focusing fields; data processing and display; computer-designer dialogue. The system makes possible to automatize the choice of the simplest ion-optical system of accelerator and optimize the main parameter of units, to produce all in the possible parameter dependences on the screen or form of plots, and, finally, to formulate and implement a calculational experiment