PURPOSE: To always obtain a device having an optimum control loop by providing means for deciding which calculating means switching means selects upon reception of information of missile speed.

CONSTITUTION: Pneumatic load to be applied to a steering wing is varied according to flying speed of a missile. That is, in dynamic characteristic of a steering driver 2 including the wing 1, the load is increased as the flying speed is increased. Then, a missile speed detector 9 detects the flying speed, a discriminator 10 selects one of rotary command calculators 5-7 optimum for the dynamic characteristic of the driver 2 at that time, and switches it by a changeover switch 8, thereby always constituting an optimum missile steering device.