The operating performance of receiving terminal power system can be improved by segmenting a multi-infeed HVDC system into a set of asynchronously operated DC-interconnected sectors using VSC-HVDC. Different DC-segmentation schemes have different impact on multi-infeed system. In order to figure out the optimal scheme, this paper firstly analyzes the characteristics of multi-infeed systems by sensitivity method and puts forward two principles of DC-segmentation. Secondly according to these principles, a DC-segmentation method based on multi-infeed interaction factor is presented and then the optimal scheme of receiving terminal power system partition is got. Finally, by applying the method, an actual large scale network is studied and the optimal DC-segmentation scheme is obtained. The effectiveness of the optimal scheme and the DC-segmentation method is verified through simulations on PSS/E. This paper has guiding significance for making DC-segmentation schemes in real projects.