By selecting a type of boom of concrete pump truck as research objective， the influence of inherent frequency on its working performance was analyzed. The Pro/Engineer software was used to establish boom system model and dimension parameter of boom was changed, and then introduced the parameter into Pro/MECHANICA module for a modal analysis. The genetic function tool kit of Matlab was used to carry out pattern recognition on the obtained data, to screen out the relevant variables, and to establish the function relationship between dimension and firstorder inherent frequency. It is able to make optimization for some dimensions in a targeted way, which is of certain reference significance for design of boom system.