A switching mechanism for a camera device includes a driving device, a first screw bar connecting to the driving device, a second screw bar connecting to the first screw bar, and a lead screw having an end coupled with the second screw bar. The first screw bar is driven by the driving device via a screw thread thereof, and the second screw bar is driven by the first screw bar via a screw thread thereof, thereby driving the lead screw for rotation. The screw nut is disposed on the lead screw and moved back and forth via the rotation of the lead screw. Two stop blocks disposed at two ends of the lead screw respectively are to limit two positions of the moved screw nut while the screw nut is moved beyond a threaded area of the lead screw, upon which time the screw nut is slightly engaged with the lead screw.