Objective To investigate the therapeutic effects of modified Lizhong Decoction on gastric and duodenal ulcers （GDU） of the spleen-stomach cold deficiency type， as well as its influence on gastric function and inflammatory mediators. Methods From April 2023 to May 2025， patients diagnosed with gastric dyspepsia of the spleen and stomach cold deficiency type at Nanyang First People's Hospital were randomly assigned to either the Western medicine group （n = 53） or the combined therapy group （n = 53）. The Western medicine group received oral rabeprazole sodium enteric-coated tablets and sucralfate suspension， while the combined therapy group received the same Western medication regimen plus modified Lizhong Decoction. Both groups underwent a 6-week treatment course. Outcomes including clinical efficacy after 6 weeks， gastric mucosal morphology scores， gastric function， levels of inflammatory mediators， mucosal repair-related factors， oxidative stress markers， quality of life before and after treatment， and treatment safety were compared between the two groups. Results The total effective rate in the combined group after 6 weeks of treatment was significantly higher than that in the Western medicine group （P < 0.05）. After 6 weeks of treatment， both groups showed reduced mucosal thickness， inflammatory cell infiltration， glandular density scores， and decreased serum levels of cholecystokinin （CCK）， motilin （MTL）， gastrin （GAS）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， nuclear factor-κB （NF-κB）， and malondialdehyde （MDA） compared to baseline， with greater reductions observed in the combined group （P < 0.05）. Additionally， serum levels of calcitonin gene-related peptide （CGRP）， trefoil factor 1 （TFF1）， epidermal growth factor （EGF）， epidermal growth factor receptor （EGFR）， and superoxide dismutase （SOD）， as well as quality-of-life scores across multiple domains， were significantly increased from baseline in both groups， with the combined group showing superior improvements （P < 0.05）. During the treatment period， the incidence of adverse reactions was 11.32% in the combined group and 5.66% in the Western medicine group， with no statistically significant difference between the two groups （P > 0.05）. Conclusion Modified Lizhong Decoction demonstrated a definite therapeutic effect on GDU of the spleen and stomach cold deficiency type， effectively improving gastric mucosal morphology， enhancing gastric function， suppressing inflammatory responses and oxidative stress， promoting the secretion of mucosal repair-related factors， improving patients' quality of life， and exhibiting favorable safety.