We generated a second‐generation CAR‐T cell targeting 5T4 with the costimulatory molecule of 4‐1BB.5T4 CAR‐T cells had specific cytotoxicity against ovarian cancer cells and secreted cytotoxic cytokines, including IFN‐γ, IL‐2 and GM‐CSF in vitro.5T4 CAR‐T cells could eradicate peritoneal and subcutaneous tumor models in vivo completely in a short time without recurrence. The gene discussed is IL2; the disease is ovarian cancer.