Objective: To investigate the status quo of postoperative mindfulness level in patients with oral and maxillofacial malignant tumors, to analyze its influencing factors, and to provide targeted support for the patients, in order to provide evidence for clinical support. Methods: A total of 452 patients with oral and maxillofacial malignant tumor who were admitted to the Peking University School of Stomatology from January 2021 to June 2021 were followed up by convenience sampling method, the general information questionnaire, the Five Facet Mindfulness Questionnaire, the 10-item perceived stress scale, and the self-esteem scale were used. The t test and analysis of variance were used to compare the scores of mindfulness of the patients with different demographic characteristics after oral and maxillofacial malignant tumors, and the differences of mindfulness levels between the patients with oral and maxillofacial malignant tumors and the normal population were compared by the Z test, Spearman correlation analysis was used to analyze the correlation between the scores of mindfulness and perceived stress and self-esteem. Multiple linear regression was used to analyze the influencing factors of mindfulness levels. Results: A total of 439 valid questionnaires were collected. The average score of postoperative mindfulness of the patients with oral and maxillofacial malignant tumor was 120.28±13.86. The scores of each dimension from high to low were as follows: act with awareness, non-judging, describing, observing, and non-reacting. Compared with the normal population, the patients with oral and maxillofacial malignant tumor showed significant differences in the total scores and scores of various dimensions after surgery. The t test and ANOVA showed that different duration of disease, age, residence, education, marital status, per capita monthly income, occupation, and medical payment methods had influences on postoperative mindfulness level of the patients with oral and maxillofacial malignant tumor (P < 0.10). Spearman correlation analysis showed that the level of mindfulness was negatively correlated with the level of perceived stress, and positively correlated with the level of self-esteem. The duration of illness, marital status, stress perception and self-esteem were included in the regression equation, suggesting that postoperative mindfulness levels of the patients with oral and maxillofacial malignant tumor had an important effect. Conclusion: Patients with oral and maxillofacial malignant tumors have low postoperative mindfulness, which is related to duration of disease, marital status, and the level of perceived stress. Medical staff should identify this group as soon as possible, provide effective psychological intervention, help to improve the level of mindfulness, and strive to improve the patients'mental health.