The invention relates to a selection method and a system of a recognition unit for Uygur language voice recognition. The method includes: corresponding text corpora are collected or prepared for to-be-recognized voice; different terms are picked out from the text corpora; the different terms are input into a morphological analyzer, corresponding term splitting results are obtained if analysis is successful, term splitting based on a tail dropping algorithm is carried out on the terms if the analysis is unsuccessful so as to obtain the splitting results, and a corresponding stem and supplementary elements of each term are obtained according to the splitting results; and the terms in the text corpora are mapped into the stems and the supplementary elements, and the high-frequency stems and supplementary elements are picked out to be used as a dictionary unit. According to the selection method and the system of the recognition unit for the Uygur language voice recognition, the Uygur language terms are split into stems and supplementary elements according to morphological change rules of Uygur language, the stems and the supplementary elements are selected to be used as the recognition unit, and therefore the problem that excessive foreign words are collected in the recognition system is solved, and recognition rates of the system are improved.