Loitering munitions integrate multiple functions such as reconnaissance, attack, and assessment. They have low usage costs, flexible combat deployment, and are difficult to detect and intercept. They have significantly enhanced the strike accuracy and ability against targets and have become important weapons in the Russia-Ukraine conflict, attracting great attention from major military powers. This paper summarizes the characteristics of loitering munitions, introduces the development status of major loitering munitions at home and abroad, including the “Switchblade” series and “BattleHawk” series of the United States, the “KUB” series and “Lancet” series of Russia, and the “Hero” series and “Harpy” series of Israel, which have practical applications. It comparatively analyzes the performance parameters of relevant loitering munitions, combs the key technologies in the development of loitering munitions, including power technology, anti-interference technology, modular technology, and intelligent cooperative combat technology, summarizes the development trends of loitering munitions, and on this basis, analyzes the combat applications of loitering munitions and the defense means against them.