Abstract: A training device for hitting a baseball is disclosed. The device includes a baseboard, an upstanding column, and flexible duct, and a transverse arm. A longitudinal rotary axle is located below the base side of the transverse arm; a rotary axle is inserted into the upper end of the upstanding column; an elastic pad is set in the engaging interface between the rotary axle and the inner wall of the upstanding column, and an engaging pipe for engaging the flexible duct is set above the end of the transverse arm. The transverse arm is rotated around the axle center of the base side, so that a baseball on a bearing disk of the flexible duct can adjust to the preset hitting position within the range of the rotation radius of the transverse arm.