The invention discloses an esophageal squamous carcinoma radical postoperative patient prognosis prediction model construction method and device, and the method comprises the steps: obtaining clinical diagnosis and treatment data and follow-up visit survival data, carrying out multi-factor Cox regression analysis on patient characteristic variables, tumor pathology characteristic variables, treatment condition variables and test index variables according to follow-up visit survival data, carrying out variable screening by utilizing a step-by-step back algorithm and an Akaike information criterion, and carrying out variable screening on the screened candidate variables again to obtain modeling variables; and performing multi-factor Cox regression analysis on modeling variables and interaction items of every two modeling variables to construct a prognosis prediction model of a patient after the esophageal squamous carcinoma radical operation, wherein the prediction variables comprise age, gender, tumor primary position, T stage, lymph node detection number, tumor size, preoperative hemoglobin level and N stage treatment mode interaction items. According to the method, the prediction accuracy can be improved, the optimal benefit group of different treatment schemes is defined, and the prognosis evaluation precision of the esophageal squamous cell carcinoma is realized.