Objective To clarify the association between the life’s crucial 9 (LC9) score and the risk of diabetic kidney disease (DKD) in patients with diabetes. Methods A cross-sectional analysis was conducted based on data from the National Health and Nutrition Examination Survey (NHANES) spanning 2005 to 2018. A total of 3 862 diabetic patients aged 20?85 years were initially enrolled. Logistic regression analysis was used to explore the association between LC9 score and DKD. Results The prevalence of DKD was 38.7%. A higher quartile of the LC9 score was associated with a lower prevalence of DKD. Multivariate analysis confirmed a negative correlation between the LC9 score and the risk of DKD: for every 10-point increase in the LC9 score, the risk of developing DKD decreased (OR=0.68, 95%CI 0.62 to 0.73); compared with the Q1 group, the risk of DKD in the Q4 group was reduced (OR=0.29, 95%CI 0.22 to 0.38). Conclusion Higher LC9 scores are associated with lower DKD risk in diabetic patients. The LC9 can be used as a tool for DKD risk stratification, and targeted interventions may help reduce the disease burden.