Today, constructing well-facilitated capital farmland on a large scale is one of the key strategic initiatives for enhancing the national capacity for food security. In order to strengthen the scientific and rational distribution of well-facilitated capital farmland, this article, starting with the discussion of ecosystem integrity of regional well-facilitated capital farmland on the basis of ecological niche theory, proposes the concept of ecological niche for well-facilitated capital farmland, and constructs “ecostate” and “ecorole” evaluation models (Ni model) of ecological niche for well-facilitated capital farmland. This is verified by studying the case of the city of Xinzheng, Henan Province, China. As the research result shows, first the condition of farmland in Xinzheng is generally good, and the farmland in the whole city is suitable for the construction of well-facilitated capital farmland covering 34,224.48 hm², 63.18% of the total area, which is mainly distributed in the southern and northwestern parts of the city. Second, the evaluation results are generally in consistency with the actual situation, which indicates that the Ni model is scientific and realistic in the evaluation of suitability for constructing well-facilitated capital farmland. Meanwhile, the Ni values are helpful for indicating the suitability for regional well-facilitated capital farmland. Third, using the most suitable ecological niche to explain standards of construction for well-facilitated capital farmland, and matching n dimension resources ecological niche along with most suitable ecological niche to evaluate well-facilitated capital farmland will convey clear ecological significance and be quite helpful to develop plans and measures for constructing well-facilitated capital farmland based on the size and changes of niche-fitness values.