Abstract: The soil environment of farmland directly affects the quality and safety of agricultural products. It is an important foundation for maintaining the 'vegetable basket' project and ensuring 'safe eating', and has received widespread attention in recent years. To determine the distribution characteristics and main influencing factors of heavy metal pollution in farmland soil, a typical watershed in Hunan Province and farmland soil along the main watershed river were studied. The watershed has prominent pollution problems, large terrain fluctuations, and a dense water network. The pollution status of Cd, Hg, As, Pb, and Cr in the soil was comprehensively evaluated using the single factor Nemerow index and potential ecological hazard index. Combining multivariate statistical analysis and geostatistical analysis, the relationship between land-use types, terrain factors, and heavy metal content was concurrently analyzed, and the spatial distribution of soil heavy metals and sources of pollution were explored. The results showed that: (1) The average concentrations of Cd, Hg, As, Pb, and Cr in the soil were 1.59, 0.19, 33.01, 229.95 and 72.78 mg/kg, respectively. Among them, the average content of Cd, As, and Pb was higher than the background values in the study area. (2) The Nemerow index showed that 77.16% of the soil sample points were seriously polluted. Compared with the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018), Cd, As, and Pb substantially exceeded the standard and were mainly distributed in the western upper reaches of the river basin. The comprehensive potential ecological hazard evaluation results showed that 3.05% of the soil samples had significant ecological risks. (3) The difference in land use resulted in significant differences in heavy metal content in the soils. The heavy metal contents of Cd, Hg, as and Pb in dry land, paddy field and orchard decreased in turn. There was a significant correlation between the elevation and content of heavy metals (except Hg) (P < 0.05), and there was no significant correlation between slope and aspect and heavy metal content (P < 0.05). (4) The source analysis results showed that Cd, As, and Pb in farmland soil of the basin were affected by the combined effects of industrial production activities, transportation, and agricultural activities. Hg and Cr are mainly came from natural activities such as parent soil material. This study has shown heavy metal pollution in the soil of the study area. The accumulation of heavy metals is significantly affected by land use type, elevation and human factors.