Objective: To investigate the functional somatic discomfort status, and to analyze the effect of job stress, hostile attribution bias and ego depletion on functional somatic discomfort in clinical nurses. Methods: In May 2019, 10 cities in Henan Province and Fujian Province were randomly selected as sampling cities. Using the stratified cluster sampling method, nurses of clinical nursing posts in 22 third class hospitals and 23 second class hospitals were selected as the research objects. The general information, job stress, hostile attribution bias, ego depletion and functional somatic discomfort of clinical nurses were investigated by self-designed general information questionnaire, Perceived Stress Scale, Social Information Processing-attribution Bias Questionnaire, Self-regulatory Fatigue Scale, Patient Health Questionnaire-15. 1200 clinical nurses included, and a total of 1159 valid questionnaires were collected, the effective rate of questionnaire collection was 96.6%. The t test was used to compare the difference of the functional somatic discomfort scores of clinical nurses with different demographic characteristicst. The influence of job stress, hostile attribution bias and ego depletion on functional somatic discomfort of clinical nurses were analyzed with Bootstrap. Results: The functional somatic discomfort score of clinical nurses was (8.95±4.38), of which 859 (74.12%) had functional somatic discomfort symptom. The functional somatic discomfort score of clinical nurses aged 36-50 years old was higher than that of 19-35 years old, the functional somatic discomfort score of clinical nurses with service age ≥5 years was higher than that of <5 years, the functional somatic discomfort score of non-permanent clinical nurses was higher than that of permanent clinical nurses, the functional somatic discomfort score of clinical nurses in tertiary hospitals was higher than that of secondary hospitals, the functional somatic discomfort score of clinical nurses in surgical departments were higher than those in non-surgical departments, and the differences were statistically significant (P<0.05). Job stress affected functional somatic discomfort through the single mediating role of hostile attribution bias, the single mediating role of ego depletion, and the chain mediating role of hostile attribution bias and ego depletion (β=0.17, 95%CI: 0.10-0.20; β=0.16, 95%CI: 0.10-0.20; β=0.07, 95%CI: 0.03-0.10; P<0.05) . Conclusion: The functional somatic discomfort symptoms of clinical nurses are significant and varied among different age, working age, employment form, hospital grade and department groups. They are affected by work stress directly and through the separate mediating effect of hostile attribution bias and ego depletion, and the chain mediating effect of hostile attribution bias and ego depletion.