Objective To investigate the health literacy level of military personnel and analyze its influencing factors so as to provide theoretical reference for formulating health education and health promotion programs. Methods From April to June in 2022, a cross-sectional survey was conducted on 9 768 military staffs in an army unit using the National Health Literacy Monitoring Questionnaire (compiled by the China Health Education Center in 2015), for 3 aspects of health knowledge and concept, healthy lifestyle and behavior, and basic skills. Six types of questions were surveyed, including scientific health concept, prevention and treatment of infectious diseases, prevention and treatment of chronic diseases, safety and first aid, basic medical treatment and health information. Chi-square test and multivariate logistic regression model were used to analyze the obtained data. Results The overall level of health literacy was 46.2% in the participants. For the 3 aspects, the basic knowledge and concept literacy level was the highest (57.8%), followed by health skill literacy level (50.2%), and the healthy lifestyle and behavior literacy level (44.7%). Among the 6 types of questions, the literacy level of safety and first aid was the highest (79.9%), and the literacy level of chronic disease prevention was the lowest (35.2%). Multivariate logistic regression analysis showed that the health literacy level of non-commissioned officers and conscripts was lower than that of officers (OR=0.342, OR=0.493), and that of civilian personnel was higher than that of officers (OR=2.078). The health literacy level of military personnel working for 6~8 years was the highest (OR=1.329). The health literacy level of military personnel aged 41 to 45 years was the highest (OR=2.613). The health literacy level was higher in the females than the males (OR=1.472). The higher the education level was, the higher the health literacy level was, among which the health literacy level of military personnel with postgraduate degree or above was the highest (OR=3.212). The military personnel whose father was a teacher had the highest level of health literacy (OR=2.679). The health literacy level of military personnel whose mothers were medical personnel was the highest (OR=1.681). The health literacy level of military personnel whose father’s degree was junior college/bachelor’s degree was the highest (OR=1.398). The health literacy level of the military personnel whose mother had a postgraduate degree or above was the lowest (OR=0.230). Conclusion The health literacy level is relatively low in the military personnel from this unit, especially in the health literacy of lifestyle behavior and disease prevention. Relevant departments should actively take effective intervention measures according to the influencing factors of health literacy to promote the comprehensive improvement of health literacy of the troop.