The overall properties of river sediment are similar to soil, while it may also contain some pollutants at the same time. Therefore, assessing its resource utilization potential and environmental risks is of great significance. This study investigated the river sediment samples systematically collected from a typical town in southern Jiangsu Province. The fertility characteristics and heavy metal contents were analyzed. By referencing relevant national standards and employing multiple pollution index methods, the sediment’s resource utilization potential and environmental risks were evaluated. The results showed that the sediments in the study area exhibited generally weak alkalinity and high nutrient contents. Specifically, the available phosphorus and rapidly available potassium contents both reached Grade I (extremely abundant), according to the nutrient classification standards of the Second National Soil Survey, while the organic matter content reached Grade II (abundant). The average contents (mg/kg) of major heavy metals in the sediments were: As (8.64), Zn (60.69), Pb (1.86), Cd (0.01), Ni (30.59), Hg (0.11), Cr (91.01), and Cu (33.24), which were generally below the pollution risk screening thresholds for alkaline soils specified in relevant national standards. Comprehensive assessment using the Nemerow index (NPI) and pollution load index (PLI) indicated that the sediments in the study area were overall in a non-polluted or slightly polluted state. Analysis using single-factor indices, specifically the geo-accumulation index (I_geo) and potential ecological risk index, showed the presence of spatially heterogeneous contamination characteristics. Localized pollution by Cd, Cu, and Hg was observed at some sampling points. In conclusion, the heavy metal contents in the investigated sediments generally comply with national standards, and the high nutrient contents suggest potential for resource utilization in agriculture. However, significant spatial heterogeneity exists among sampling points, with individual points exhibiting slight pollution levels, which requires attention and exploration of resource utilization pathways beyond agricultural application.