Abstract: In this paper, a three-dimensional finite element for the drillingrig foundation is built for studying the dynamic characteristics anddesign of the drilling rig foundation. Through analysis of its modes, the dynamiccharacteristics of the drilling rig foundation are discussed. On the basis of theanalysis of the dynamic characteristics for the drilling rig foundation, theeffect of basic frame on the dynamic characteristics of the drilling rigfoundation is investigated. According to the conclusions drawn from theanalysis, thedynamic design or modification of drilling rig foundation structures is madeby optimization of frames. The method put forward by the paper can be used in the dynamic design or modification of drilling rigfoundation structures.