To provide a vehicle steering device capable of stably executing motor control using an alternative motor rotation angle even when a value obtained by converting the resolution of a rotation angle sensor used for detection of the alternative motor rotation angle into a motor rotation angle is within a range of 90-180°.

When abnormalities are detected in a motor rotation angle detected by a motor rotation angle sensor, a microcomputer executes alternative control using an alternative motor rotation angle on the basis of a detection value of a steering sensor in place of the motor rotation angle. In addition, the microcomputer calculates a d-axis current command value Id* that cancels a q-axis current component (a first component Iq1) of a q-axis current command value Iq* in which a phase delay corresponding to a conversion resolution Δθ0 is generated based on the alternative control.