The invention relates to the technical field of iron and steel smelting and discloses a casting powder adding device. The device comprises a storage tank, a bearing cart and a conveying bin, wherein the output of the storage tank is arranged over the head end of the conveying bin, a filtering net is arranged in the middle of the storage tank, casting powder falls onto the conveying bin through theoutput of the storage tank, the head end of the conveying bin is rotationally connected with the bearing cart through a rotary screw, the tail end of the conveying bin is inclined downwards relativeto the head end of the conveying bin, the inclination degree can be adjusted, and a vibrating crystalization platform drives the tail end of the conveying bin to swing up and down so that the castingpowder can uniformly fall into a crystallizer in the center of the vibrating crystalization platform. According to the casting powder adding device, the inclination degree and the vibration amplitudeof the conveying bin can be adjusted by adjusting the height of a nut instead of by using extra media or consuming other energy, thus, the casting powder adding rate can be adjusted, requirements of different steel grades at different pulling rates can be met, and the device is simple in structure, convenient to operate and wide in application range and occupies little space.