A humidifying and fresh-keeping device for a refrigerator is provided, including a device container and a top cover. The container has a drawer for storing fruits and vegetables, and a containing chamber is disposed at one side of the container. A drawer-type water tank is disposed in the containing chamber, with a water storing box at one end and an ultrasonic humidifying device at the other end. A supply air box is disposed at a wind outlet of the ultrasonic humidifying device, and an atomizing air duct is distributed in the container. An inlet of the atomizing air duct corresponds to an outlet of the supply air box, and outlets of the atomizing air duct are provided in the containertop cover. As a result, the fruits and vegetables preserved in the container have an environment humidity of 90-95%, and can be kept fresh in seven days.