Objective To explore the clinical features and the influencing factors of the multidisciplinary diagnostic and treatment models for elderly patients with mental disorders. Methods A total of 6 272 elderly patients with mental disorders who were hospitalized in Shandong Daizhuang Hospital from January 2017 to December 2021 were selected as study subjects. A self-designed questionnaire was used to collect general and disease information from the patients. Chi-square test and Mann-Whitney U test were used to analyze the clinical characteristics of elderly patients with mental disorders and the influencing factors for the selection of multidisciplinary treatment mode， and Binomial Logistic regression was used to analyze the factors influencing the multidisciplinary diagnostic and treatment model. Results The distribution of elderly patients with mental disorders by age group was 65-70 years old （3 508 cases，55.9%），71-75 years old （1 613 cases，25.7%），76-80 years old （786 cases， 12.5%），81-85 years old （294 cases，4.7%），and ≥ 86 years old（71 cases， 1.1%）. The top three composition ratios of elderly mental disorders were depressive disorders （2 796 cases，44.58%），organic brain disorders （894 cases，14.25%），and bipolar disorders （681 cases，10.86%），and depressive disorders were the most common mental disorders in old age. The somatic comorbidity rate was high in elderly patients with mental disorders， amounting to 93.8% （5 883 cases）. Elderly patients with mental disorders with somatic comorbidity（χ2 =484.344，P＜ 0.05），older age（Z=-19.188，P＜ 0.05），female（χ2 =4.172，P ＜ 0.05）and living in towns and cities （χ2 =11.510，P ＜ 0.05） would be more inclined to choose a multidisciplinary diagnostic and treatment model，and the differences were statistically significant. Elderly patients with mental disorders who chose a multidisciplinary diagnostic and treatment model had few hospital days （Z=-13.203，P ＜ 0.05）and less hospitalization costs （Z=-11.000，P ＜ 0.05）. Older age，somatic comorbidity，female and living in towns and cities were influencing factors for the choice of multidisciplinary diagnostic and treatment model in elderly patients with mental disorders （OR＞ 1，P＜ 0.05）. Conclusions Depressive disorder is the most common mental disorder in the elderly population. Elderly patients with mental disorders exhibit a high comorbidity rate of physical illnesses， leading a significant proportion of them to opt for multidisciplinary treatment models. Age， comorbid physical illnesses，and place of residence are influencing factors in whether elderly patients with mental disorders choose multidisciplinary treatment approaches.