The invention relates to a device and a method for coloring red Chinese sand pears after harvesting, and the method comprises the following steps: standing the Chinese sand pears which achieve the physiological maturity stage and are not colored under an environment with UV-B (ultraviolet-B) luminous intensity of 1-2 mu mol.m-2.s-1, luminous intensity of white light of 3-4 mu mol.m-2.s-1, averagetemperature of 25-29 DEG C, and average relative humidity of 55-75% for 5-10 days. The device comprises a closed storage room for placing the Chinese sand pears, wherein an UV-B light source and a white light source are mounted at the top of the storage room, a temperature control device and a humidification device are mounted on the side wall, and a ventilation opening is arranged at the bottom.After the Chinese sand pears are harvested, the Chinese sand pears are placed in the environment with the controllable temperature and the humidity, the fruits with relatively sufficient, stable and uniform coloring can be obtained by performing continuous irradiation under the artificial light source for a period of time, and the device and the method are specially used for promoting the coloring of the red Chinese sand pears, and can promote the synthesis of anthocyanin in the red Chinese sand pears in a quicker manner and improve the appearance quality.