Objective To analyze the health knowledge of retired military cadres and the main influencing factors. Methods A total of 350 retired military cadres were selected from the record of Changhai Hospital of Naval Medical University (Second Military Medical University) by simple random sampling method, and a self-made health knowledge questionnaire was issued to collect the basic information and health knowledge scores. Health knowledge was divided into basic health knowledge, health skill knowledge, and chronic disease prevention and control related knowledge. A score of 80% or more of the total score indicated that they had appropriate health knowledge. Chi square test was used to analyze the relationship between health knowledge and basic information of retired military cadres. Multivariate logistic regression model was used to analyze the main influencing factors of health knowledge. Results A total of 349 valid questionnaires were collected, and the response rate was 99.71%. The passing rates of the total score of health knowledge, basic health knowledge, health skill knowledge and chronic disease prevention and control related knowledge were 19.20% (67/349), 67.62% (236/349), 20.06% (70/349) and 12.03% (42/349), respectively. The results of univariate analysis showed that there were significant differences in the passing rates of the total score of health knowledge among the retired military cadres of different genders, ages, educational levels and medical learning experiences (all P<0.01). Multivariate logistic regression analysis showed that education level and medical learning experiences were the main influencing factors of health knowledge (odds ratio[OR]=5.133, 95% confidence interval[CI]2.207-11.939, P<0.01; OR=4.359, 95% CI 2.300-8.263, P<0.01). Conclusion Retired military cadres have a good understanding of basic health knowledge, but poor understanding of health skills and chronic disease prevention and control related knowledge. Military health care facilities and medical personnel should carry out appropriate health education for different groups of people.