The active support system can provide the capacity of surface figure control and positioning for large optical telescope primary mirror, hence the active control technology of monolithic mirror surface figure and co-phasing technique of segmented mirror has been developed rapidly. The applications of active support system and actuator in large optical telescope in recent years are reviewed and summarized. Several common active support systems and actuators are concludes. Their features are compared, and the relationship between active support system and actuator is proposed. The future development of active support system and actuator applied to telescope primary mirror is prospected in the end.