[Objective] Investigating the coupling relationship between the risk of soil erosion and the natural suitability of human settlements in Guyuan City, Ningxia Hui Autonomous Region provides theoretical support for the prevention and control of soil erosion in small watersheds, and thereby contributes more to the improvement of human settlements. [Methods] The PSR model and the human settlement index model were used to calculate the risk of soil erosion in a small watershed as well as the natural suitability for human settlement. The correlation and the coupling degree of the two factors were calculated to analyze their coupling coordination degree and the coupling coordination type. [Results] ① The small watersheds with moderate and high risk of soil erosion accounted for 28% of the area, and were located in the southwest and southeast. Small watersheds that were rated as unsuitable for human settlement accounted for 12% of the area, located in the southern of Xiji County and Northeastern Longde County. ② The correlation coefficient between soil erosion risk and natural suitability of human settlements was 0.61. 74% of small watersheds were found to have high coupling degree and benign resonance coupling areas, and 67% of small watersheds were found to be coordinated development and highly coordinated development areas. ③ There were 75, 36, 79, and 114 watersheds classified as coordination and synchronization type small watersheds, imbalance and co-loss type small watersheds, soil erosion lag type small watersheds, and human settlement lag type small watersheds, respectively. [Conclusion] ① Soil erosion and human settlement in Guyuan City had high correlation, high coupling degree, and significant mutual promotion effects. ② There were 79 small watersheds with lagging risk of soil erosion that needed to be controlled, and 36 dysfunctional co-loss type small watersheds should be treated and reconstructed according to the local conditions.