A method for controlling a parallel kinematic mechanism machine and control device therefor, which includes the steps of (1) obtaining each actuator command based on kinematic parameters; (2) calculating loads exerted by the weight of each component of a machine; (3) obtaining loads in the direction of axis of each actuator; (4) decomposing loads in the direction of axis of each strut into directions of axes of the first and second universal joints; (5) obtaining the amounts of elastic deformation of each element; (6) converting approximately the amounts of elastic deformation of each universal joint to displacement in the direction of axis of each actuator; (7) subtracting displacement in the direction of axis of each actuator obtained at steps (5) and (6) from each actuator command to renew each actuator command, and controlling the machine according to each renewed actuator command.