Abstract: Aiming at the issues existed in current identification method of industrial critical technology in value chain upgrading of manufacturing enterprise, such as mainly depends on qualitative analysis, evaluation criteria is uncertain and lack of initial technology analysis method, a systematic identification approach of industrial critical technology which was integrated industrial technology roadmapping, IDEF0 and entropy weight method was proposed. Through defining the industrial critical technology based value chain upgrading theory, the evaluation criteria was proposed from operational level; consider the properties of industrial value chain and associated features of industrial technology chain, a novel two chain identification method for generating initial list of critical technology was proposed which integrated the practice of industrial technology roadmapping and IDEF0; to solve the problem of complexity and subjectivity in the assessment process of critical technology, a weight calculation approach of evaluation criteria based on triangular fuzzy numbers and entropy weight method was proposed too; the final list of industrial critical technology was determined through the construction of industry critical technology matrix analysis model. The approach was validated by case studies on identifying critical technologies in Guangdong LED industrial technology roadmapping.