Based on the design theories of steel tower for electric transmission line,an optimization principle of the feed support system of large aperture spherical radio telescope is discussed,and the optimization target functions of the feed support system are advanced in this paper.Then,combining with a genetic algorithm of extremum for complicated functions and a digital three dimension simulation technique,an optimization system for the feed support system is programmed by VC language.The study of a case,the optimization of the feed support system in the planned Dawodang site,shows that the applied forces on a support system with many towers are more reasonable than that on a support system with few towers,but the project investment of support system with many towers is greater,Therefore,a 4-tower support system is suggested for the feed support system of large aperture spherical radio telescope.