[Objective] The heavy metal pollution of Coix seed and soil in its producing area were studied to provide a scientific basis for the sustainable development of the Guizhou Coix seed industry and the prevention and control of heavy metals in the soil of its origin.[Methods] The Coix seed and the soil of its producing area were used as the test samples. The soil pH value, organic matter, cation exchange capacity, and five heavy metal elements, such as cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), and nickel (Ni) were determined using geographic information system and single-factor pollution risk assessment methods to explore the spatial distribution of soil heavy metals and the impact of soil heavy metal pollution on the quality and safety of Coix seeds.[Results] ① The Cd, Pb, Zn, Cu, and Ni contents in the soil ranged from 0.01 to 1.35, 10.09 to 34.70, 80.39 to 236.36, 22.54 to 131.42, and 26.75 to 137.76 mg/kg, respectively, of which the maximum values of Cd, Cu, and Ni were higher than the current national standard (GB15618-2018), indicating that there was a certain range of Cd, Cu, and Ni pollution risk in the soil in the study area. The comprehensive pollution index was 1.94, and the pollution level was light pollution. ② The contents of Cd, Pb, Zn, Cu, and Ni in the Coix seed ranged from not detected to 0.027, 0.179 to 1.348, 42.615 to 58.961, 10.028 to 16.244, and 0.552 to 5.045 mg/kg, respectively. Cd did not exceed the standard, while Pb, Zn, Cu, and Ni exceeded the standard by varying degrees, with the exceeding rates being 90%, 25%, 75%, and 30%, respectively. Coix seed had a strong cumulative effect of Pb.[Conclusion] By simultaneously collecting soil samples and corresponding Coix seed samples, the analysis results can be used to evaluate the impact of soil heavy metal pollution on the quality and safety of Coix seed.