An optical element driving mechanism is provided. The optical element driving mechanism has a main axis, and includes a fixed portion, a movable portion, and a driving assembly. The fixed portion includes a housing, a base, and a frame. The base is fixedly connected to the housing along the main axis. The frame is disposed in the housing, and has a plurality of protruding columns extending along the main axis. The protruding columns have a first section and a second section, and the first section is closer to the base than the second section. The movable portion is movable relative to the fixed portion, and carries an optical element. The shortest distance between the first section and the movable portion is longer than the shortest distance between the second section and the movable portion. The driving assembly drives the movable portion to move relative to the fixed portion.