The natural environment of human settlements is the basis of human development, while the scientific evaluation of human settlement natural environment is not only the premise to improve the carrying capacity of resources and environment but also the basic work to achieve sustainable development. Based on previous research, this article further discussed the evaluation methods of human settlement environmental suitability by taking Tibet as an example. The results show that: (1) The evaluation method based on conditional rules was more suitable for the evaluation of human settlement environmental suitability in Tibet; (2) More than three-quarters of the land in Tibet are unsuitable for human habitation, with most of them distributed in the northwestern part of Tibet; the area of the regions of critical suitability accounts for 16.78% of the total area of Tibet, mainly located in the YarlungZangbo River, Nyangqu River, and Lhasa River basins, the upper reaches of the Lancang River, and the northern parts of Shannan and Linzhi; the areal proportion of suitable regions was only 5.83%, concentrating in the southeast of Tibet, river valleys of the YarlungZangbo River, Nyangqu River, and Lhasa River, and valley oasis in the upper reaches of the Lancang River; (3) The distributions of different types of settlements are highly coupled with human settlement environmental suitability zones in Tibet, the proportion of town and village settlements reflecting human activities had a positive relationship with the degree of human settlement environmental suitability, while negative connection was found between the proportion of sites of pastoral people/ancient temples and relics and degree of human settlement environmental suitability. The results also validate the reliability of our evaluation method and classification of human settlement environmental suitability.