an optical signal processing apparatus based on movable tilted reflection mirror comprises a movable tilted reflection mirror unit and a micro actuator . the micro actuator is used to control and actuate the relative location and position of the movable reflection mirror unit with respect to the optical transmission path of light signals . to control the light intensity of the incoming optical signals being reflected toward output ports and the light intensity of the optical signals transmitted forward to output ports , the light intensity is adjusted in terms of the location of the movable tilted reflection mirror unit which is determined by electrically controlling said micro - actuator . the movable tilted reflection mirror unit comprises at least one reflective mirror plane , which can be a flat mirror plane , a shaped mirror plane , or a curved mirror plane . a plurality of such optical processing apparatuses can be integrated to form an optical signal processing apparatus with the function of variable optical attenuation , optical switching , optical multiplexing / demultiplexing , and optical add / drop .