Daiwang Fu (Mansion of Prince Dai) belongs to the provincial cultural relic protection units of Jiangsu. It has color paintings (without the ground layer) drawn in the late Qing Dynasty, but as time goes by, they have suffered from many kinds of diseases, including surface powdering, paint layer cracking, shedding and mold breeding, etc. Through on-site investigations and detections, the design scheme of first-aid conservation and restoration was made for the color paintings. According to the scheme, the conservation and restoration of Daiwang Fu paintings were carried out, and expected results were achieved. The protection technology could provide a reference for the conservation of the same type of ancient architectural color paintings.