A ball-hitting trainer is provided with a base combined with a flexible shaft that may bend in all directions. The flexible shaft is structured with a helical spring and a flexible wire. The flexible wire is wound around an outside gap of the helical spring so as to make the flexible wire helical and wrap the whole helical spring. The body of flexible shaft is covered by a plurality of shock absorbers, and a free end of the flexible shaft is connected to a cup-shaped body; thus the ball-hitting trainer is formed and a ball may be placed in the cup-shaped body for practice of ball hitting.