It is of great strategic significance for an enterprise, a trade and even a country to evaluate sustainable technology scientifically and rationally. The essay thinks sustainable technology is compatible and symbiotic with the scientific & technological, economic, social, human and natural environment systems, and thus it reaps comprehensive benefits continuously of economy, society, ecology and others. After have analyzed and clarified the basic characteristics of sustainable technology, the essay constructs correspondingly a system of 19 evaluation indexes to sustainable technology, and proposes a comprehensive evaluation method of sustainable technology with fuzzy comprehensive evaluation (FCE) which is scientific, rational, effective and widely applied. Through the multi-level and multi-operator models of FCE, the essay further analyzes the general method and procedure of comprehensive evaluation to sustainable technology with a practical example. Therefore, the essay solves preliminarily the urgent problem to evaluate sustainable technology in a scientific, rational, standardized and quantitative way.