The invention provides a bucket rotating machine which comprises a horizontal rack, a conveying component, a bucket retaining component, a bucket rotating component and a driving component. The conveying component is fixed on a support through a diamond-shaped seat-containing bearing and a mounting plate, the bucket rotating component is fixed on the support through a mounting frame, the bucket retaining component is fixed on a side plate through a flat plate, a bucket handle can be rotated to a fixed direction, the problem that the bucket handle and a grabbing device interfere is solved thoroughly, bucket dropping probability is lowered greatly, and stacking efficiency is improved. The bucket rotating machine is simple and compact in structure, so that grabbing stability of rear-end workstations is improved; the bucket rotating machine is low in manufacturing cost, and can provide six bucket rotating workstations at the same time and allow simultaneous rotating of the six buckets at most, thereby being high in bucket rotating efficiency; a retaining sleeve is of a conical structure, thereby being high in compatibility, and the bucket rotating machine is suitable for bucket rotating of iron buckets and plastic buckets.