Abstract: Combining the basic theory of cloud model and the process of ecological impact evaluation for land consolidation,the rule of ecological impact evaluation and the cloud models of the antecedent and the consequent are constructed.By translating the uncertain factor conditions into quantitative values with the uncertain illation based on cloud model,the evaluation factor scores and comprehensive scores of Miaotan land are computed.The results are compared with those of composite index computation method and fuzzy comprehensive assessment.