Advanced gastric cancer (AGC) is difficult to treat with poor prognosis. Despite various possible treatments, the median survival time of such patients remains unsatisfactory. Therefore, new therapeutic approaches or combinations need to be further explored. We herein reported a case of a 54-year-old male patient who was initially diagnosed with HER2-negative advanced gastric cancer. Based on previous studies and patient's desire, we made a therapeutic plan: the combination of concurrent radiochemotherapy and immune checkpoint blockade therapy. After about 4 months of combined therapy, the patient showed satisfactory complete response to tumor lesions even metastatic lesions (CR, disappearance of all target lesions). In summary, the combination of concurrent SOX regimen chemotherapy, stomach radiotherapy and PD-1 antibody immunotherapy is effective in the treatment of advanced gastric cancer.