The invention discloses an exposure device and method for a silicon wafer alignment mark. The exposure device is composed of a light source module, a lighting module, an energy monitoring module, an imaging module, a mounting main frame, a silicon wafer height sensor, a reticle stage, a silicon wafer stage and a control module. The device comprises two or more illumination-imaging units which are capable of simultaneously exposing two or more alignment marks on the silicon wafer surface. The device and method save alignment label exposure time, improve the production efficiency of an IC production line and saves an IC production cost.