An optical element driving mechanism for corresponding to an optical module, the optical element driving mechanism including a fixed portion, a movable portion, and a first driving assembly. The fixed portion has an aperture. The movable portion is for connecting to an optical element and is movable relative to the fixed portion. The first driving assembly is for driving the movable portion to move relative to the fixed portion. The fixed portion has an elongated structure, and the fixed portion further comprises a first end. The fixed portion further comprising a second end, wherein the first end and the second end are arranged along a first direction. A shortest distance between the optical sensing element and the first end is shorter than a shortest distance between the optical sensing element and the second end.