The broad-spectrum antibacterial activity of cathelicidin-DM has been proven,and this study intends to explore its other biological activities to further promote its clinical application.cathelicidin-DM was synthesized by solid-phase synthesis,and the antioxidant activity,hemolytic activity,lectin activity,cytotoxicity and tumor cytotoxicity were detected.The results show that cathelicidin-DM has strong scavenging activity for ABTS+ free radicals,but relatively weak scavenging activity for DPPH free radicals,and has certain cytotoxicity to the RAW 264.7.Hemolytic activity,lectin activity,and tumor cell toxicity are not obvious.cathelicidin-DM not only has broad-spectrum antibacterial activity,but also has antioxidant activity.Solving its cytotoxicity will be a major pre-clinical challenge.Or it can be used as a biological antioxidant.