Abstract:China put forward the major strategy of targeted poverty alleviation in 2013, and implemented the “most stringent assessment and evaluation” system to ensure that the work of poverty alleviation is pragmatic, the process of poverty alleviation is solid and the result of poverty alleviation is real. Targeted poverty alleviation assessment is an important means to improve the effectiveness of national targeted poverty alleviation, which is of great significance to fight against poverty alleviation and promote the modernization of national governance system and governance capacity. Based on the practice of the third-party evaluation of the effectiveness of national targeted poverty alleviation, this paper discusses the differentiation law of rural poverty and its scientific cognition, summarizes the theory and technology system of national targeted poverty alleviation evaluation, and deeply analyzes the application and contribution of evaluation theory and technology in the evaluation survey over the years. Results show that the “island effect” and “marginal diminishing effect” of rural poverty, and the supply-demand structure between the government's “support” and the farmers' “poverty” are the scientific significance of implementing the effectiveness assessment of targeted poverty alleviation. They require in-depth assessment to promote rectification and effectively improve the performance of targeted poverty alleviation. The theoretical cognition and practical needs of rural poverty are the important basis for establishing assessment objectives and developing assessment plan, and plays a direct guiding role in refining the assessment indicators of antipoverty effectiveness, exploring the connotation of indicators and formulating evaluation work plans. Theoretical system of national third-party assessment on the effectiveness of targeted poverty alleviation is a comprehensive system including key technologies, supporting technologies, package support system, and big data platform. It has successfully supported the national effectiveness assessment of targeted poverty alleviation from 2016 to 2020, and has played the role of “baton”, “quality inspection instrument”, and “propeller”, providing references for the assessment and scientific decision-making for poverty alleviation.