A neck warmer with adjustable function comprises a warmer body with first opening and second opening; and a first ear accommodating hole and a second ear accommodating hole, which can be hung on the ear so that the warmer body adopts single-layer waring form, or fold the warmer body in half, hang the first and second ear accommodating holes on the ears, so that the warmer body adopts a double-layer wearing form. The warmer body is made of seamless and comfortable high-stretch fabric. A certain number of ear accommodating holes are formed on both sides and middle of the warmer body. In order to cope with the external environment including air temperature and severe haze weather, the warmer body adopts a design structure that can be worn in a single layer or folded in half to form a double-layer structure, so as to achieve the purpose of multi-layer protection.