xiu2014, did you take a look at your photos in full resolution? Most of them have incredibly shallow depth of field, only a tiny portion of photographed object is sharp, the rest is blurry. No wonder Photoscan can't match these photos well. Also, top ring of photos is shot from too radically different perspective in relation to bottom rings. Photos within any given ring of photos align well to one another because each next photo is shot from only slightly different perspective (low angle between camera positions). But difference in perspective between any photo from top ring and any photo from other rings is just too significant.
Cheers,
Andrew