China is a populous agricultural country, the arable land is the most basic resources which is needed for agricultural production, the quality of arable land has a direct impact on the entire agricultural production and development ,so to carry out the Evaluation of Farmland is a very important foundation work which is advantage to know china’s arable land resources and to improve the efficiency of use for arable land and promote the development of modern agricultural , and which is helpful to further identify china fertility status of cultivated soils, the distribution of nutrients, soil fertility and agricultural land degradation, etc., so as to achieve the realization of agricultural modernization and to improve the comprehensive capacity of agricultural production. This paper use visualization of spatial data mining technology which is used to research and apply on soil fertility evaluation, which is put the technology of spatial data mining and visualization technology, GIS, technology tightly integrated, that makes a research to the elements of soil fertility, yield and other data mining, and achieve the application of visualization of spatial data mining techniques in the evaluation of soil fertility, this application is more conducive to promotion and application of precision agriculture for variable rate fertilization, variable spraying, at the same time it provides real-time, accurate decision making basis for agricultural production management department, to promote the transformation of traditional agriculture to modern agriculture, which has important theoretical significance and practical value.