The technology readiness assessment is widely used in multidisciplinary manufacturing areas. The identification of critical technical elements is a key step in the assessment of technology readiness levels, and is an important guarantee for reducing risks in project or product development and reducing development costs. The identification of traditional critical technical elements generally adopts the expert screening method. Through discussion, the list of critical technical elements of final consistency is obtained, the results are subjective and uncertain, resulting in the loss or redundancy of critical technical elements, that directly affects the technical readiness quantitative identification . For this reason, a method of critical technology element identification based on FAHP principle is proposed in this paper. Firstly, the expert establishes the fuzzy judgment matrix according to the criterion and the importance degree scale, and then adjusts to the fuzzy consistency matrix, then solves the importance degree of each sub-technical element, and finally identifies the critical technical elements according to the important measurement evaluation results and passes the example. The pair verified its validity. It is concluded that the method combines qualitative analysis and quantitative analysis to reduce the influence of uncertainty factors and has good engineering application value.