An actuator control method, wherein the method uses time optimal control and comprises: a calculation step of calculating a switching time t1 at which an acceleration output is switched to a deceleration output and an end time t2 of the deceleration output expressed by time elapsed from a calculation time t0 at which calculation for control is performed using a maximum acceleration αp and a maximum deceleration αm, which are measured in advance, at the time of the maximum output of control force of the actuator; and a control output step of setting the control force of the actuator to a maximum acceleration output from the calculation time t0 to the switching time t1, setting the control force of the actuator to a maximum deceleration output from the switching time t1 to the end time t2, and ending the output of the control force at the end time t2, characterized in that the method also calculates and updates the switching time t1 and the end time t2 by repeating the calculation step at each preset fixed period of time of trajectory recalculation within the control period, wherein at the calculation step, in a case where a trajectory from a position at the calculation time t0 to a target position at the end time t2 is represented by a combination of two quadratic curves in contact with each other, V0 is the velocity at the calculation time, and a deviation between a target position and a controlled variable is taken to be X, the switching time t1 and the end time t2 are calculated using Expression and Expression below t 1 = − 2 α 1 − α 2 V 0 ± 4 α 1 − α 2 2 V 0 2 − 4 α 1 − α 2 V 0 2 − 2 X α 2 α 1 2 α 1 α 1 − α 2 t 2 = − α 1 − α 2 t 1 − V 0 α 2 where α1 and α2 are determined from below table 1: [Table. 1] A1 X>0 V 0 >0 V 0 2 /2 α m>X α 1= α m, α 2= α p A2 V 0 2 /2 α m<X α 1= α p, α 2= α m A3 V 0 <0 α 1= α p, α 2= α m A4 X<0 V 0 >0 α 1= α m, α 2= α p A5 V 0 <0 V 0 2 /2 α p>X α 1= α m, α 2= α p A6 V 0 2 /2 α p<X α 1= α p, α 2= α m a calculation step of calculating a switching time t1 at which an acceleration output is switched to a deceleration output and an end time t2 of the deceleration output expressed by time elapsed from a calculation time t0 at which calculation for control is performed using a maximum acceleration αp and a maximum deceleration αm, which are measured in advance, at the time of the maximum output of control force of the actuator; and a control output step of setting the control force of the actuator to a maximum acceleration output from the calculation time t0 to the switching time t1, setting the control force of the actuator to a maximum deceleration output from the switching time t1 to the end time t2, and ending the output of the control force at the end time t2, characterized in that the method also calculates and updates the switching time t1 and the end time t2 by repeating the calculation step at each preset fixed period of time of trajectory recalculation within the control period, wherein at the calculation step, in a case where a trajectory from a position at the calculation time t0 to a target position at the end time t2 is represented by a combination of two quadratic curves in contact with each other, V0 is the velocity at the calculation time, and a deviation between a target position and a controlled variable is taken to be X, the switching time t1 and the end time t2 are calculated using Expression and Expression below t 1 = − 2 α 1 − α 2 V 0 ± 4 α 1 − α 2 2 V 0 2 − 4 α 1 − α 2 V 0 2 − 2 X α 2 α 1 2 α 1 α 1 − α 2 t 2 = − α 1 − α 2 t 1 − V 0 α 2 where α1 and α2 are determined from below table 1: [Table. 1] A1 X>0 V 0 >0 V 0 2 /2 α m>X α 1= α m, α 2= α p A2 V 0 2 /2 α m<X α 1= α p, α 2= α m A3 V 0 <0 α 1= α p, α 2= α m A4 X<0 V 0 >0 α 1= α m, α 2= α p A5 V 0 <0 V 0 2 /2 α p>X α 1= α m, α 2= α p A6 V 0 2 /2 α p<X α 1= α p, α 2= α m