Can I boot from a .tib image?
I have a file backup from Internal SDD to External HDD.If the SDD failed, could I boot from the file backup in HDD(which are .tib files, right?)?
It's not possible to boot from a file-level backup or mount it, as it doesn't contain information about the partitions structure. You'll need to create an Entire PC or Partition backup to be able to restore the system after fall.
If you only have a file-level backup, you'll need to install the operating system from scratch and then recover individual files/folders from your backup.