Esophageal squamous cell cancer (ESCC) has a high incidence in China. Although the fast development of immune check point inhibitors (ICIs), the rate of pCR is limited with the mode of ICIs combined with neoadjuvant radiochemotherapy. The rate of pCR under ICIs combined with neoadjuvant radiochemotherapy was reported around 50%, which means more than half of those patients could not obtain pCR in reality. In order to explore a more effective mode of neoadjuvant therapy for ESCC, we designed this study to evaluate the effect of PD-1/CTLA-4 bi-antibody, termed as cadonilizumab, combined with neoadjuvant radiochemotherapy in local advanced ESCC.