A low rotational speed gear module includes a fixed tube member, a rotational sleeve, a first planetary gear set, a sun gear, and a second planetary gear set. The fixed tube member includes a first inner gear. The rotational sleeve includes a second inner gear. The first planetary gear set includes a fixing plate, first planetary gears fixed to one side of the fixing plate, and a driven gear fixed to the other side of the fixing plate. The first planetary gear is engaged at one side with the sun gear and engaged at another side with the first inner gear. The second planetary gear set includes second planetary gears. The second planetary gears is engaged at one side with the driven gear and engaged at another side with the first inner gear and the second inner gear.