Objective To explore the relationship between health literacy of chronic diseases and the effect of blood glucose control in newly diagnosed and prediabetes patients. Methods A total of 180 newly diagnosed and prediabetes patients treated in the Western Theater Command General Hospital from January 2021 to January 2023 were selected, including 94 newly diagnosed and 86 prediabetes patients. The health literacy of chronic diseases in these patients was evaluated by using the health literacy management scale (HeLMS) developed by Jordan et al. The differences of clinical general information and blood glucose control between patients with adequate and insufficient health literacy were analyzed. Results Among the 180 patients, the total score of information acquisition ability, communication and interaction ability, willingness to improve health, willingness for financial support, total score of health literacy, and adequate proportion of health literacy assessed by HeLMS were (35.54 ± 7.21), (33.02 ± 8.15), (15.54 ± 3.92), (7.10 ± 0.98), (91.87 ± 7.28), and 51.67%, respectively. The age of patients with adequate health literacy in the newly diagnosed diabetes group was (52.23 ± 7.15) years old, which was significantly lower than that of patients with insufficient health literacy (P<0.05). The proportions of patients with high school education and above, monthly income ≥ 3000 yuan, and relatives engaged in medical work were 68.09%, 68.09%, and 34.04%, respectively, which were significantly higher than those of patients with insufficient health literacy (P<0.05). The age of patients with adequate health literacy in prediabetes group was (82.23 ± 4.15) years old, which was significantly lower than that of patients with insufficient health literacy (P<0.05). The proportions of patients with high school education and above, monthly income ≥ 3000 yuan, number of children ≥ 2, and relatives engaged in medical work were 65.22%, 67.39%, 34.78%, and 41.30%, respectively, which were significantly higher than those of patients with insufficient health literacy (P<0.05). The fasting blood glucose, glycosylated hemoglobin and 2h postprandial blood glucose of patients with adequate health literacy in the newly diagnosed diabetes group after treatment were (6.43 ± 0.93) mmol/L, (6.02 ± 0.91)% and (7.71 ± 1.01) mmol/L, respectively, which were significantly lower than those of patients with insufficient health literacy (P<0.05). The fasting blood glucose, glycosylated hemoglobin and 2h postprandial blood glucose in patients with adequate health literacy in prediabetes group after treatment were (5.21 ± 0.37) mmol/L, (5.20 ± 0.40)% and (6.20 ± 0.92) mmol/L, respectively, which were significantly lower than those in patients with insufficient health literacy (P<0.05). Conclusion The chronic disease health literacy of prediabetes and new-onset patients is related to the age, education and monthly income level, number of children, relatives engaged in medical work of patients, and the level of health literacy is helpful to the control of blood glucose.