Immunotherapies, mainly immune checkpoint inhibitors (ICIs), have revolutionized cancer treatment strategies over the past decade, but their limitations have limited clinical applications. Tumor-infiltrating lymphocyte (TIL) therapy is a type of adoptive cell therapy (ACT), which collects infiltrating lymphocytes at the tumor site and expands them in vitro to obtain TIL final products cloned by various T-cell receptors, subsequently reinfused TIL into the patient, which is effective for the treatment of solid tumors. The approval of Lifileucel for commercialization marks the success of TIL therapy. This review summarizes the current status of clinical trials of TIL treatment. In addition, it is suggested that the current research trend of TIL should focus on improving the survival time of TIL in vivo, reducing drug toxicity, and searching for prognostic markers. Finally, it is expected that TIL therapy can be applied to a more wide range of clinical treatments.