The electric actuator of TFAX Linear Actuator series mainly used to drive HAVC two-port and three-port valves, the force ranges from 500N to 3000N. Adopting high performance AC reversible synchronous motor to prevent the actuator stopping running. Using high strength steel gear and shaft can lengthen the service life of the actuators; the current opening can be observed at any angle by lamp and movable valve position indicator. Unique encoding design makes the valve positioning more accurate. In conclusion, the TFAX series actuators can be widely and effectively used in the field of HAVC.