A multifunction warning device is provided for being used as a flashlight, a warning sign or an illuminating traffic baton. The multifunction warning device mainly contains a base, plural legs, and a rechargeable device. The base has a top portion and a bottom portion having a first electric socket therein. Each of the plural legs is pivotally secured to the base. Each of the plural legs has plural illuminating elements thereon. The plural illuminating elements are electrically connected to the first electric socket. The rechargeable device contains a shell, plural rechargeable batteries, a charging circuit, and a discharging circuit. The shell has a charging connector detachably plugged into the first electric socket and thereby electric power is provided from the rechargeable batteries to the illuminating elements. The plural legs are stretchable to be a support and retractable to be assembled as a baton.