Personnel competency assessment is the prerequisite and foundation for governments and enterprises to establish job requirements, select and appoint excellent talents, develop training plans, optimize talent structure, and promote development. Because personnel competency has potentiality, fuzziness, and dynamicity, and assessment experts have personal preferences, limited rationality, and experience limitations, it is very difficult to make objective and accurate assessment of key personnel"s post competency. As a data fusion method for uncertain information, evidence theory fits the natural process of key personnel assessment.Therefore, according to the natural practical operation process of key personnel competency assessment, this paper analyzes the reasoning process of various data, information features and evidence fusion in personnel competency assessment, considers the complexity and multi-stage of the assessment process, and considers the limited rationality and preference of assessment experts, and proposes a multi-stage multi-source evidence fusion personnel competency assessment decision-making method based on preference evidence theory. Finally, a case study is conducted by taking the professional title review of a university as an example.