Through the correlation analysis of statistical data of provinces and autonomous regions, this paper has comprehensively, systematically and quantitativelystudied the natural geography, geological environment, socioeconomic, geochemical and hydrogeological constraints of endemic diseases, cancer and common diseases in mainland China. In order to prevent the rational design of medical experimental plan, provide a scientific basis. The results show that, the occurrence of different human diseases is subject to different environmental conditions. Keshan disease, Kashin-Beck disease, endemic goiter and fluorosis, in addition to soil selenium, groundwater iodine and fluoride, but also by a variety of environmental factors; Total nitrogen in soil has an promote effect to gastric cancer and liver cancer. The amount of nitrogen fertilizer has an effect to rectal cancer, pancreatic cancer and lymphatic cancer, and soil arsenic has significant inhibitory effect to lung cancer, pancreatic cancer and lymphatic cancer. River water hardness, salinity and soil calcium, magnesium and other elements for a variety of cancers may also have inhibitory effect. Cerebrovascular disease and myocardial infarction have shown the features of urban population in cold and droughts in the north; Chronic obstructive pulmonary disease and respiratory tract infections show the features of the population in the mountain mining and smelting industries; Chronic nephropathy reflects the characteristics of arsenic and sulfur poisoning in plateau areas; Alzheimer disease shows the characteristics of people in farming areas. The average content of elements in sediments of water system, the county territory of 26 longevity counties in China are relatively high compared with the national average, and the human beneficial elements are relatively high; while the harmful elements in human bodies are relatively low. If we make full use of soil (stream sediment) geochemical measurement data, combined with the results of this study, it is possible to greatly refine the spatial distribution prediction maps of population diseases in mainland China. The author believes that by improving the climatic and geographical conditions of residence and increasing the intake of certain chemical elements in an appropriate form(Especially the food chain diet structure), it will certainly play an important role in reducing the occurrence and development of diseases and improving human health.