The invention provides an automatic feeding device for colored sand. The automatic feeding device for the colored sand is simple in structure, high in production efficiency, and stable and reliable in work. The device comprises a rack, a plurality of material distributing boxes for storing different basic colored sand, a plurality of reaction kettles which are arranged in the length direction of the rack, at least one material conveying trolley which is positioned between the corresponding material distributing box and the corresponding reaction kettle and used for supplying the basic colored sand into the reaction kettles, and conveyors which are connected between the material conveying trolleys and the material distributing boxes and used for conveying the materials to the material conveying trolleys, wherein each material conveying trolley comprises a trolley body, idler wheels which are arranged on the bottom end of the trolley body and are in rolling connection with the rack, a weighting module which is arranged on the bottom end of the trolley body and used for weighting, a driving motor for driving the trolley body to roll, a material discharging port which is formed in one side of the trolley body, and a driving cylinder for driving the material discharging port to close. With the adoption of the device, the degree of automation of the conveying and production processes of the basic colored sand can be effectively improved, so that the production efficiency of the colored sand can be effectively improved.