As a kind of new antibiotics, antimicrobial peptides (AMPs) which are small molecular polypeptides composed of 10~100 amino acid residues, have been paid much attention for their broad-spectrum antibacterial activity, thermal stability and unique mechanism of action. In recent years, studies have shown that the possibility of bacterial drug-resistance has been greatly reduced for the multi-target action mechanisms, including membrane-targeted, non-targeted and immune regulation of AMPs in vivo. AMPs combat pathogen infection and promote apoptosis of cancer cells in vivo. Furthermore, they are also used as chemotherapeutic agents against virus and antibacterial materials for hospital settings, with a broad scope in biomedical field. This review article covers the recent developments related to antimicrobial mechanisms. Meanwhile, scientific problems in potential medicine application fields of AMPs are analyzed and the resolution strategies are also offered to provide new insights into the further research and development of AMPs.