Several epidemiological studies have demonstrated the risk factors for fall, while few studies investigated the association between frailty and risk of fall in diabetic patients aged ≥45 years. In this multicity observational study, participants with type 2 diabetes aged ≥45 years were enrolled. Frailty status was measured by a frailty index (FI) of deficit accumulation. We used multivariable regression models to examine the relationship between frailty and fall in diabetic patients, and further investigated the associations between frailty and fall in varied subgroups. A total of 2049 participants with type 2 diabetes were identified in our study. Our results showed a per-SD and a per-0.01 increment of FI were associated with an increased risk of fall, with a fully-adjusted OR of 1.89 (95% confidence interval (CI): 1.50, 2.38), 1.06 (95% CI: 1.04, 1.09), respectively. The effects were magnified when frailty was considered as dichotomous, with an OR of 3.08 (95% CI: 2.18, 4.34). In further subgroup analyses, we found that the females, the older, rural residents, individuals with no sitting toilet, people with poor balance performance and those in poor health status were susceptible to fall. Especially, for the risk of fall in the older, a per-SD increase of FI corresponded to an OR of 2.46 (95% CI: 1.68, 3.62). Frailty was associated with a higher risk of fall in people with type 2 diabetes, and the effects were higher in vulnerable groups. This evidence suggests that more attention should be paid to vulnerable groups for fall prevention.