how to restore photo library

Are you trying to import the old Photos Library?

Try to open it in Photos instead. Where is the recovered library now? If it is not in the Pictures folder, move it into the Pictures folder. Do not keep it on your Desktop or in Documents, if these folders are syncing with iCloud.

• Select the Photos Library in the Finder, then ctrl-click it and use the command "Open with Photos".
• If that does not work, try to repair the library:
  • Select the Photos Library in the Finder, then hold down the key combination ⌥⌘ firmly, while you are double clicking the Photos icon in the Dock to launch Photos.
  • When the dialog to repair a library appears release the keys.
  • Wait, until the library has been repaired. It can take a very long time, depending on the size of the library.

If you cannot repair the library, it may have become damaged beyond repair when the Trash has started to delete the library. Then you will need to restore a copy from your Time Machine backup, or any other backup you have made.

Or have you been using iCloud Photos and your photos are still in iCloud? In that case you can simply create a new, empty library and let it sync with iCloud and download your photos back from iCloud. This will be faster than trying to repair the library and uploading it again to iCloud.

To download a fresh copy from iCloud:

• Hold down the options key ⌥ while launching Photos. Select to create a new library, when the dialog to select a library appears.
• When the new, empty library opens in Photos, make it the System Photo Library in the Photos > Settings > General: Click "Use as System Photos Library".
• Then make it the iCloud Photos Library: In the Photos > Settings > iCloud set the checkmark for iCloud Photos.
• Close the Settings panel and wait for your photos to come back from iCloud.