The invention discloses a Chinese word segmentation method based on a hash table dictionary structure. The Chinese word segmentation method comprises the following steps: A, performing pretreatment to a to-be-treated document; B, performing positive maximum matching scanning segmentation and negative maximum matching scanning segmentation to each treatment block; C, comparing the results of two scanning of each treatment block, if the segmentation results of the two scanning are the same, outputting a positive segmentation result, if the segmentation results are different, respectively calculating the segmentation numbers S, the separate word dictionary word numbers D, the non-dictionary word numbers N and the maximum word lengths L of the positive maximum scanning result and the negative maximum scanning result respectively; D, comparing and analyzing data produced in step 3 in combination with the method and then outputting a right result. The Chinese word segmentation method has the benefits that the matching efficiency in the segmentation process is improved, the comparison rate after positive and negative scanning can be improved, and the efficiency of two-way maximum matching algorithm is improved fundamentally.