A governing valve drive mechanism for driving a governing valve which opens/closes a steam flow path, through which steam serving as a working fluid of a steam turbine circulates, with a valve body in order tc regulate a flow rate of the steam, comprising: a valve body advancing/retreating mechanism which advances and retreats the valve body toward and from the steam flow path; first and second electric actuators (23A, 23B) which include a rotational drive source and a conversion section which converts rotation of the rotational drive source into linear motion; a first connection switching section which is capable of individually connecting and releasing the first conversion mechanism with respect to the valve body advancing/retreating mechanism; a second connection switching section which is capable of individually connecting and releasing the second conversion mechanism with respect to the valve body advancing/retreating mechanism; and a control unit which controls operations of the rotational drive source and the first and second connection switching sections; each of the first and second connection switching sections including: - a coupling housing which is connected with the valve body advancing/retreating mechanism and which has an actuator side rod insertion hole on an end face opposite to the valve body advancing/retreating mechanism; - an actuator side rod wherein a tip portion thereof is removably inserted into the actuator side rod insertion hole; characterized in that each of the first and second connection switching sections includes: - a pair of engagement key shafts (316, 316) which provided on both sides of the actuator side rod in a state where the actuator side rod is interposed there between and which are formed in a columnar shape orthogonal to the central axis of the actuator side rod; - engagement keys (316k, 316k) integrally formed with the pair of engagement key shafts (316, 316); - engagement recessed portions (319, 319) capable of engaging with the engagement keys (316k, 316k) and formed on an outer circumferential surface of the actuator side rod; wherein the engagement key shafts (316, 316) rotate around axes thereof, and accordingly, the engagement keys (316k, 316k) advance and retract toward and from the engagement recessed portions (319, 319). a valve body advancing/retreating mechanism which advances and retreats the valve body toward and from the steam flow path; first and second electric actuators (23A, 23B) which include a rotational drive source and a conversion section which converts rotation of the rotational drive source into linear motion; a first connection switching section which is capable of individually connecting and releasing the first conversion mechanism with respect to the valve body advancing/retreating mechanism; a second connection switching section which is capable of individually connecting and releasing the second conversion mechanism with respect to the valve body advancing/retreating mechanism; and a control unit which controls operations of the rotational drive source and the first and second connection switching sections; each of the first and second connection switching sections including: - a coupling housing which is connected with the valve body advancing/retreating mechanism and which has an actuator side rod insertion hole on an end face opposite to the valve body advancing/retreating mechanism; - an actuator side rod wherein a tip portion thereof is removably inserted into the actuator side rod insertion hole; characterized in that each of the first and second connection switching sections includes: - a pair of engagement key shafts (316, 316) which provided on both sides of the actuator side rod in a state where the actuator side rod is interposed there between and which are formed in a columnar shape orthogonal to the central axis of the actuator side rod; - engagement keys (316k, 316k) integrally formed with the pair of engagement key shafts (316, 316); - engagement recessed portions (319, 319) capable of engaging with the engagement keys (316k, 316k) and formed on an outer circumferential surface of the actuator side rod; wherein the engagement key shafts (316, 316) rotate around axes thereof, and accordingly, the engagement keys (316k, 316k) advance and retract toward and from the engagement recessed portions (319, 319). - a coupling housing which is connected with the valve body advancing/retreating mechanism and which has an actuator side rod insertion hole on an end face opposite to the valve body advancing/retreating mechanism; - an actuator side rod wherein a tip portion thereof is removably inserted into the actuator side rod insertion hole; characterized in that each of the first and second connection switching sections includes: - a pair of engagement key shafts (316, 316) which provided on both sides of the actuator side rod in a state where the actuator side rod is interposed there between and which are formed in a columnar shape orthogonal to the central axis of the actuator side rod; - a pair of engagement key shafts (316, 316) which provided on both sides of the actuator side rod in a state where the actuator side rod is interposed there between and which are formed in a columnar shape orthogonal to the central axis of the actuator side rod; - engagement keys (316k, 316k) integrally formed with the pair of engagement key shafts (316, 316); - engagement recessed portions (319, 319) capable of engaging with the engagement keys (316k, 316k) and formed on an outer circumferential surface of the actuator side rod;