A lens displacement device includes a flexible piece, a fixed element and a mobile element. The flexible piece has a support, a flexible part and an oscillation absorber. The flexible part connects to the support and at least one gap exists between the flexible part and the support. The oscillation absorber is installed in the gap between the flexible part and the support. Moreover, the fixed element couples to the support of the flexible piece, and the mobile element couples to the flexible part of the flexible piece. Furthermore, the flexible part of the flexible piece is deformed in shape for providing a restoration force with the mobile element. A manufacturing process of the flexible piece is also disclosed.