The invention discloses a special tool for upwards drilling from the lower part of a concrete roof. The special tool for upwards drilling from the lower part of the concrete roof comprises an electricimpact drill, a supporting platform and an electric impact drill lifting device. The electric impact drill is upwards perpendicularly fixed onto the supporting platform; the supporting platform is fixed onto the top end of the electric impact drill lifting device formed by a lifting frame, two socket and spigot main pipes and a drive mechanism; the two socket and spigot main pipes are perpendicularly fixed onto a bottom plate; the lifting frame can be movably inserted onto the two socket and spigot main pipes, and a drive mechanism support rod is perpendicularly fixed onto the bottom plate, so that the two socket and spigot main pipes and the drive mechanism support rod form a triangle; and the drive mechanism is arranged between the support rod and the lifting frame. The special tool forupwards drilling from the lower part of the concrete roof provided by the invention is simple in structure, the error of perpendicularity of an embedded steel bar bottom hole is reduced, and the forming quality of the embedded steel bar bottom hole is improved. By using the special tool for upwards drilling from the lower part of the concrete roof provided by the invention, the labor intensity ofconstructors is greatly reduced, and the forming efficiency of the embedded steel bar bottom hole is improved.