A screw-driven fan device includes a screw, a screw nut, a fan, and a connecting unit. An external edge of the screw has a rolling groove formed thereon and a groove formed alternately with the rolling groove. The screw nut, disposed on the screw, has a linking portion. The fan has a rotary axle with a hole formed thereon for screw passing through. The fan further has blades surrounding the rotary axle. The hole has a flange formed on an interior side thereof and engaged with the groove. The connecting unit has a space therein such that the fan can be placed in the space.