Objective To analyze the serum 25-hydroxyvitamin D[25-(OH)D]level in the patients with type 2 diabetes mellitus(T2DM),and to construct a risk prediction model for osteoporosis occurrence.Methods A total of 542 patients with T2DM treated in this hospital from January 2021 to July 2023 were se-lected and devided into the osteoporosis group(n=57)and non-osteoporosis group(n=485)according to whether or not osteoporosis occurred.The serum 25-(OH)D level in the patients with T2DM was detected.The risk factors of T2DM complicating osteoporosis were analyzed by the univariate and multivariate Logistic regression.The risk prediction model was established,and the predictive value of the risk prediction model for T2DM complicating osteoporosis was analyzed by drawing the receiver operating characteristic(ROC)curve.Results Among 542 patients with T2DM,the cases and proportions of 25-(OH)D sufficient,insufficient,defi-cient and severely deficient were as follows:18 cases(3.32%),156 cases(28.78%),324 cases(59.78%)and 44 cases(8.12%),respectively.The proportions of males in the 25-(OH)D sufficient group and 25-(OH)D insufficient group were higher than those of females,the proportion of male in the deficiency group and severe deficiency group was lower than that of female(P<0.05).The multivariate Logistic analysis results showed that age≥60 years old,prolonged course of T2DM,female and lack of serum 25-(OH)D level were the risk factors for T2DM complicating osteoporosis(OR=1.813,1.706,2.162,1.654,P<0.05).The body mass in-dex(BMI)increase was a protective factor for T2DM complicating osteoporosis(OR=0.542,P<0.05).The above factors were included in the risk prediction model:logit(P)=-13.799+age×0.595-BMI×0.612+T2DM duration×0.534+sex×0.771+serum 25-(OH)D level×0.503.The patients with T2DM complica-ting osteoporosis were included in the positive category and those with T2DM without osteoporosis were in-cluded in the negative category.The ROC curve for predicting the occurrence of T2DM complicating osteopo-rosis was drawn according to the risk prediction model.The results showed that when logit(P)>5.67,the area under the curve(AUC)was 0.917.The diagnostic sensitivity and specificity were 78.95%and 87.63%respectively.Conclusion The osteoporosis occurrence in T2DM patients is related to the age≥60 years old,prolonged course of T2DM,female,lack of serum 25-(OH)D level and BMI decrease,etc.