A Chimeric Switch Receptor, which was constructed by fusing the PD1 extracellular ligand binding domain to the CD28 intracellular costimulatory domain, was designed to target PD-L 1 positive tumors . In this single-arm, open-label, one center, dose escalation clinical study, the main purpose is to determine the safety and efficacy of infusion of autologous Chimeric Switch Receptor modified T cells (CSR T) in adult patients with PD-L1 positive, recurrent or metastatic malignant tumors.