Aim. If gastric cancer can be detected through early screening, and scientific and reasonable intervention methods can be selected in time, the condition can be effectively controlled. Routine nursing has been unable to obtain satisfactory results, and the effect on improving the compliance of the examiner is not outstanding. The research aims to estimate the outcome of nursing based on health belief combined with knowledge, belief, and practice on gastroscopy in patients with gastric cancer. Methods. 126 patients with clinically diagnosed gastric cancer in the Number Two Hospital of Baoding from May 2020 to May 2022 were randomly divided into belief guidance group and mode group, with 63 instances each. The mode group was intervened via the mode of knowledge, belief, and practice, and the belief guidance group was intervened via the nursing based on health belief on the basis of the mode group. Before and after the nursing, the health belief, examination compliance, inappropriateness, and negative emotion in different time periods were contrasted between the two groups. Results. After the nursing, the scores of health belief scale in the belief guidance group were enhanced than those in the mode group; the compliance rate of the belief guidance group was markedly enhanced than that of the mode group, and the inappropriateness during the insertion and examination was lower than that of the mode group; the scores of self-rating anxiety scale (SAS) and self-rating depression scale (SDS) in the two groups preinsertion and postnursing were markedly lower than those in the mode group. Conclusion. Nursing based on health belief guidance united with knowledge, belief, and practice mode nursing can advance the health belief and compliance of gastroscopy in patients with gastric cancer, reduce discomfort, and effectively advance the negative emotions of patients. It is worthy of clinical application.