The invention provides a method for extruding an inner transverse rib of a cylindrical piece. Themethod comprises the following steps: (1) extruding a blank downwards by a left male die and a right male die; (2) moving the left male die and the right male die to the left and the right respectively to press working zones at the
head parts of theleft male die and the right male die into a cylinder wall; (3) rotating a female die, and keeping the left male die and the right male die moving to the left and the right; (4) stopping the horizontal separation motion of the left male die and the right male die, extruding the blank again by the left male die and the right male die, and simultaneously keeping the female die rotating to form a cylinder wall with slant
fiber texture; (5) stopping the female die from rotating, and combining the left male die and the right male die; (6) after combining the left male die and the right male die, integrally moving the left male die and the right male die downwards to extrude the blank; (7) separating the left male die and the right male die, and rotating the female die; (8) after finishing
extrusion and rotation, drawing the left male die and the right male die close to each other; and (9) moving the left male die and the right male die upwards, and pushing an extruded piece out by an ejector rod so as to finish a complete
extrusion and rotation process. Accordingto the method, the
fiber texture of a cylinder body is distributed spirally and is slant,and the transverse and longitudinal comprehensive performance of the extruded piece is improved.