[Ubuntu]error mounting can't read superblock to recovery

I mounted a HHD disk with my Ubuntu system to store huge amount of files. Once I use rm -rf data/ to delete one data directory, my disk crashed and can not be mounted. When I tried to mount the disk, it prompted the message "error mounting can't read superblock". How to rescue it?

I tried command fsck -y /dev/sdb, it prompted information that I need to recover the superblock from backups. It suggested two backup block id and I tried one. Now , everything is Ok. But, it becomes slow to mount the disk. I have no idea why this happened.

Just logging this situation.