The invention relates to an annular stirring device special for a portable cement agitator. The annular stirring device comprises four supporting feet. An annular mounting rack is welded to the upper ends of the four supporting feet. Four lower mounting vanes are symmetrically arranged on the upper end face of the annular mounting rack. A lower agitating barrel abuts against the inner wall of the annular mounting rack. Four upper mounting vanes are symmetrically arranged on the outer wall of the lower agitating barrel. Each upper mounting vane is connected with the corresponding lower mounting vane through a bolt. A circular outlet is formed in the bottom end of the interior of the lower agitating barrel. An agitating branched chain is mounted at the upper end of the lower agitating barrel through a bearing. The agitating branched chain comprises an annular concave ring, and the lower end of the annular concave ring is connected with the lower agitating barrel through the bearing. The problems that existing automatic cement agitating equipment is complex in structure, high in price, inconvenient to use and the like can be solved, the high-efficiency rapid cement agitating function can be achieved, and the annular stirring device has the advantages of being simple in structure, low in labor intensity, low in cost, high in agitating speed and the like and is suitable for household type housing construction.