An optical element driving mechanism, corresponding to an optical sensing element with an optical sensing surface, comprising: a fixed portion, having an aperture corresponding to the optical sensing element, an optical axis (3-O) perpendicular to the optical sensing surface passing through the aperture, wherein in a first direction (1-D1), the aperture is closer to one end of the fixed portion than to the other end of the fixed portion; a movable portion, movably disposed on the fixed portion, comprising an optical element and a sliding part, wherein the fixed portion comprises a rail corresponding to the sliding part; a first driving assembly at least partially disposed on the fixed portion, driving the optical element to move in the first direction (1-D1); and a positioning assembly disposed on the fixed portion or the movable portion, wherein the positioning assembly limits the movable portion to a first terminal position or a second terminal position relative to the fixed portion; wherein when viewed along the optical axis (3-O), the optical element at least partially overlaps the aperture when the movable portion is in the first terminal position; wherein the first driving assembly comprises: a first driving coil disposed on the fixed portion; a positioning pin located in the first driving coil; and a first driving magnet connected to the movable portion, moving relative to the first driving coil in the first direction (1-D1); wherein the positioning pin is made of iron, or any suitable magnetic conductive material; wherein the length of the positioning pin is greater than the length of the first driving coil, so that a range of motion of the first driving magnet is greater than a length of the first driving coil; wherein the positioning assembly comprises: a positioning element corresponding to the movable portion; and a second driving assembly driving the positioning element to move relative to the fixed portion in a second direction (1-D2) perpendicular to the first direction (1-D1) for locking or unlocking the movable portion. a fixed portion, having an aperture corresponding to the optical sensing element, an optical axis (3-O) perpendicular to the optical sensing surface passing through the aperture, wherein in a first direction (1-D1), the aperture is closer to one end of the fixed portion than to the other end of the fixed portion; a movable portion, movably disposed on the fixed portion, comprising an optical element and a sliding part, wherein the fixed portion comprises a rail corresponding to the sliding part; a first driving assembly at least partially disposed on the fixed portion, driving the optical element to move in the first direction (1-D1); and a positioning assembly disposed on the fixed portion or the movable portion, wherein the positioning assembly limits the movable portion to a first terminal position or a second terminal position relative to the fixed portion; wherein when viewed along the optical axis (3-O), the optical element at least partially overlaps the aperture when the movable portion is in the first terminal position; wherein the first driving assembly comprises: a first driving coil disposed on the fixed portion; a positioning pin located in the first driving coil; and a first driving magnet connected to the movable portion, moving relative to the first driving coil in the first direction (1-D1); wherein the positioning pin is made of iron, or any suitable magnetic conductive material; wherein the length of the positioning pin is greater than the length of the first driving coil, so that a range of motion of the first driving magnet is greater than a length of the first driving coil; wherein the positioning assembly comprises: a positioning element corresponding to the movable portion; and a second driving assembly driving the positioning element to move relative to the fixed portion in a second direction (1-D2) perpendicular to the first direction (1-D1) for locking or unlocking the movable portion. a first driving coil disposed on the fixed portion; a positioning pin located in the first driving coil; and a first driving magnet connected to the movable portion, moving relative to the first driving coil in the first direction (1-D1); wherein the positioning pin is made of iron, or any suitable magnetic conductive material; wherein the length of the positioning pin is greater than the length of the first driving coil, so that a range of motion of the first driving magnet is greater than a length of the first driving coil; wherein the positioning assembly comprises: a positioning element corresponding to the movable portion; and a second driving assembly driving the positioning element to move relative to the fixed portion in a second direction (1-D2) perpendicular to the first direction (1-D1) for locking or unlocking the movable portion. a positioning element corresponding to the movable portion; and a second driving assembly driving the positioning element to move relative to the fixed portion in a second direction (1-D2) perpendicular to the first direction (1-D1) for locking or unlocking the movable portion.