Objective:To investigate and analyze the psychological stress status and influencing factors of medical staff in comprehensive grade A hospitals.Methods:This was a cross-sectional survey using a convenient sampling method. A questionnaire survey was conducted among 2 048 staff members of the Affiliated Hospital of Qingdao University from February 25 to June 16, 2022. The questionnaires included the Self-rating Stress Questionnaire (SSQ-53), the Self-rating Anxiety Scale, and the Self-rating Depression Scale. A total of 2 048 questionnaires were distributed and 2 048 were collected. Among them, 2 006 (97.95%) were valid questionnaires, and 2 006 medical staff were ultimately included in the analysis. According to the results of the scale, they were divided into the increased psychological stress group and the non increased psychological stress group. Descriptive analysis, independent sample t-test/chi-square test, correlation analysis, and other methods were used to analyze the psychological stress status of medical staff and the distribution of related factors, and multivariate logistic regression was used to analyze their influencing factors. Results:A total of 310 (15.5%) out of 2 006 study subjects showed increased psychological stress. Women had a statistically significant increase in physical (14.7% vs 8.0%, χ2=12.40, P<0.001) and emotional dimensions (18.2% vs 13.5%, χ2=5.04, P=0.025) of stress compared to men. The level of psychological stress was positively correlated with anxiety and depression ( r=0.810, 0.749, respectively, P<0.001). Univariate analysis showed that those who were women ( χ2=6.76, P=0.009), with low education backgrounds ( Z=-2.50, P=0.012), nurses ( χ2=15.72, P<0.001), or working in emergency departments ( χ2=13.64, P=0.009) had a higher rate of increased psychological stress, while the serum calcium level in the increased psychological stress group was lower than that in the non increased psychological stress group ( t=2.82, P=0.005). Multivariate analysis showed that low educational backgrounds ( OR=2.238, 95% CI: 1.090-4.597, P=0.028) and working in emergency department ( OR=1.589, 95% CI: 1.012-2.493, P=0.044) were independent risk factors for increased psychological stress of medical staff. Working in administrative and logistics departments ( OR=0.466, 95% CI: 0.229-0.950, P=0.036) and serum calcium level ( OR=0.213, 95% CI: 0.059-0.760, P=0.017) were negatively correlated with increased psychological stress. Conclusions:In comprehensive grade A hospitals, medical staff working in the emergency department or with lower educational backgrounds face greater psychological stress. Serum calcium level is negatively correlated with increased psychological stress, but the causal relationship needs further study.