To provide a tire abnormality detection device capable of detecting local abnormality of a tire with high reliability.

The tire abnormality detection device 10 comprises a torque sensor 1 which is used for the output control of a vehicular electric power steering device 20 to detect the steering torque from a steering wheel 12 applied against the steering load torque from a steered wheel, and a signal processing means 2 to extract the vibration composition attributable to the local abnormality of the tire mounted on the steered wheel included in the steering load torque from the output signal of the torque sensor 1.