Abstract: The accurate acquisition of geometric parameter is the key condition for high quality imaging of cone-beam CT. Therefore, the accurate acquisition of cone-beam CT geometric parameter is one of the focuses of CT technology research. In this paper, a model body was designed, which is easy to be made and operated, and is integrated. The parallel dual-wire method of obtaining the geometric parameter for cone-beam CT was presented. The principle and formula derivation of the important parameter of the parallel dual-wire method were introduced. Through the simulation calculation, the robustness of the method was demonstrated. Finally, the method was verified through experiment. The result shows that the parallel dual-wire method has the advantages of high precision and good robustness. It is a good method of obtaining the geometric parameter of the cone-beam CT.