Objective To investigate the relationship of non-verbal facial expression features and aggression risk of patients with severe mental disorders. Methods This study is a cross-sectional study. The study was carried out in 15 community hospitals in Beijing from September to December in 2019. A total of 30 patients with severe mental disorders who had aggressive behavior and met the International Classification of Diseases-10 diagnostic criteria were included. Modified Overt Aggression Scale（ MOAS）， Patient Health Questionnaire 9-items（ PHQ-9） and Generalized Anxiety Disorder Scales 7-items（ GAD-7） were applied to evaluate aggression risk， depression and anxiety respectively. Openface extracted 5 action units（ AU）： AU4 （brow lowerer），AU5（ upper lid raiser）， AU7（ lid tightener）， AU20（ lip stretcher）， and AU23（ lip tightener）. The intensity and duration of each AU were calculated， and the correlation between AU index and the total score