Hard disk fixing structure and computer case

The invention provides a hard disk fixing structure comprising a fixing plate and a cover body arranged on the fixing plate. The cover body is provided with a side plate vertical to the fixing plate and a top plate opposite to the fixing plate. The side plate is provided with a first through hole and a first fastening piece matched with the first through hole, and the first fastening piece is used for fixing a hard disk with a first size in the hard disk fixing structure after passing through the first through hole. The top plate is provided with a second through hole and a second fastening piece matched with the second through hole, the second fastening piece is used for fixing a hard disk with a second size in the hard disk fixing structure after passing through the second through hole, and the first size is different from the second size. The hard disk fixing structure can be used for containing hard disks with different sizes.