Purpose: To explore the clinical effect of systematic nursing intervention guided by the health belief model in inpatients with chronic schizophrenia, focusing on analyzing the improvement value of this intervention program on patients’ self-efficacy, social function and quality of life. Methods: The case subjects were all patients with chronic schizophrenia who were treated in Nanjing You’an Hospital. The data entry period was from January 2024 to December 2025. A total of 80 cases were screened. The grouping method was a random number table method, with 40 cases evenly matched in each case. The control group received routine care, while the experimental group received special nursing intervention based on the health belief model. After 3 months of continuous intervention, the differences in self-efficacy level, social functional status and quality of life between the two groups of patients were evaluated. Results: Before the intervention, there was no statistical difference in the scores of various indicators between the two groups (p > 0.05); after adopting different nursing models, the self-efficacy scores and quality of life scores of the patients in the experimental group were higher than those of the control group, and the social function scores were better than those of the control group, and the difference was statistically significant (p < 0.05). Conclusion: Health belief model nursing intervention for patients with chronic schizophrenia can effectively correct patients’ negative health cognition, improve disease management self-efficacy, reduce social functional impairment, and comprehensively improve patients’ physical and mental quality of life, which is worthy of clinical promotion and application.