This study is a single-center, prospective, open-label, randomized controlled clinical study, and the purpose of this study was to compare the pathological complete response rate (PCR) of patients with locally advanced rectal cancer treated with short-course radiotherapy sequential Tislelizumab combined with CapeOX (group A) versus short-course radiotherapy sequential CapeOX (group B). A total of 100 patients with locally advanced rectal cancer will be enrolled in the study. These patients were randomly assigned to the experimental group (group A) and the control group (group B) in a ratio of 1:1.