Chlorin e6 (Ce6) has been extensively researched and developed as an antitumor therapy. Ce6 is a highly effective photosensitizer and sonosensitizer with promising future applications in photodynamic therapy, dynamic acoustic therapy, and combined acoustic and light therapy for tumors. Ce6 is also being studied for other applications in fluorescence navigation, antibacterials, and plant growth regulation. Here we review the role and research status of Ce6 in tumor therapy and the problems and challenges of its clinical application. Other biomedical effects of Ce6 are also briefly discussed. Despite the difficulties in clinical application, Ce6 has significant advantages in photodynamic therapy (PDT)/sonodynamic therapy (SDT) against cancer and offers several possibilities in clinical utility.