This article provides a brief introduction to Natural Language Processing and basic knowledge of Chinese Word Segmentation at first. Chinese Word Segmentation is a process of turning a series of Chinese characters into a series of Chinese words with some rules. As the fundamental component of Chinese information processing, it is wildly used in correlative areas. Accordingly, research on Chinese Word Segmentation has important theoretic and realistic meaning. In this paper, we mainly introduces the challenge in Chinese Word Segmentation, and presented the categories of Chinese Word Segmentation method.