A pill grasping method comprises rotating a grasping arm with a nozzle to a predetermined initial position driven by a driving mechanism, rotating a number of pill storage cases to position one of the pill storage cases with a set number of pills to a predetermined grasping pill position driven by an actuating mechanism, rotating the grasping arm to enter into the corresponding pill storage case, starting a pump to generate a vacuum in the nozzle for sucking a pill, and determining if an actual pressure value in a pipe connecting the nozzle to the pump is less than a predetermined pressure value. The grasping arm is rotated to the predetermined initial position when the actual pressure value is less than the predetermined pressure value.
