The invention discloses an optical directional device with a light-screening component for indicating position by measuring relative translation of a reference surface. The inventive device comprises an optical unit and a process unit for processing optical signal. The optical unit includes a light-emitting component for forming a light dot on a reference surface, a light sensing component, and a light-screening component. The light-screening component has a light-penetrated hole and matches with the light sensing component to decide measurement range, which make the lighting point gets far away from the measurement range when the optical directional device gets far away from the reference surface.