Objective To analyze the risk factors of inadvertent intraoperative hypothermia (IIH) in the patients with non-in vitro cardiac hybrid operation,and to construct a nomogram prediction model. Methods The clinical data in 429 cases of non-in vitro cardiac hybrid surgery in this hospital during 2019-2022 were collected.Whether IIH occurring served as the outcome indicator.The univariate and multivariate logistic regression analyses were used to screen out the significant independent influencing factors,and the no-mogram model was constructed.The area under the receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the model,the calibration curve was used to evaluate the consistency of the mod-el,and the Bootstrap resampling method was used for conducting the internal validation.Results The inci-dence rate of IIH in 429 cases was 72.26％.The multivariate logistic regression analysis showed that the basal body temperature,intraoperative heparin use amount,BMI,warming methods and anesthesia duration were the independent influencing factors for the IIH occurrence in the patients with non-in vitro cardiac hybrid op-eration.The AUC value of the constructed nomogram model was 0.916 (95％CI:0.885-0.947) with good discrimination and consistency.Conclusion The nomogram model constructed in this study has the high pre-dictive value,which could provide the reference data for carrying out clinical IIH preventive measures.