In a tire uniformity measurement, accurate tire uniformity is obtained from a measurement waveform immediately after a rotation of a tire is switched from a normal rotation direction to a reverse rotation direction. A tire uniformity testing device of the present invention includes a measurement unit 108 that obtains a force variation from a uniformity waveform corrected by a correction unit 109 that corrects the uniformity waveform so as to eliminate a shift gradient α existing in the uniformity waveform measured after a rotation of a tire T1 is reversed, and further includes an air-outflow regulation member 220 that regulates an from flowing into a tire T2 when a drum 205 retreats or advances.