What happened after emptying Trash Bin?
When we emptied Trash Bin (excluding secure emptying), what we actually deleted is not the file itself. The operating system simply loses the access of the file, as the pointers between files and file system index are deleted. The space occupied by deleted files is marked as "available to reuse", so the deleted files remain physically intact on the drive until they are overwritten by other files. The files will be only deleted when they are overwritten by new files. In order to prevent overwriting we need to stop using the Mac immediately if we want to recover deleted data from Mac Trash.
How to recover deleted files from Mac Trash?
To undo emptied Trash on Mac lion, we need the help from a third-party application - Mac Trash Recovery. Here we humbly recommend Wondershare Data Recovery for Mac, a professional and easy-to-use data recovery for Mac users with any computer-level, is capable to recover deleted, formatted and inaccessible documents, images, videos, archives, songs, etc. from Mac desktop, Macbook and iPod, digital camera, USB drives, mobile phones and other storage media. With the user-friendly interface, you can recover trash Mac just with a few mouse clicks. If the space isn't overwritten, your deleted files can be recovered with 100%.
Tips:
Keep in mind: Never download and install any program in the place where you lost your files, for this could overwrite your lost data. Download and install it on another partition.
If you're using Windows OS, you need to download a Windows version of Wondershare Data Recovery: 
Install and run the Mac data recovery software on your computer. Then follow next steps.
Step 1 Choose Lost File Recovery mode
"Lost File Recovery" can recover deleted files from a partition or removable media, no matter deleted by Command + Delete or emptied from the Trash.
This recovery option is recommended at first, for it takes you only a few minutes to retrieve deleted files from Mac Trash. If you can't find your deleted file with this mode, you can try "Raw Recovery" later, which can recover tons of files including those lost long time ago, more time consumed accordingly.

Step2 Scan the location of Trash on Mac
Select the logical drive where you deleted your files, if you have more than one drives on your Mac. Then click on "Scan" to search your deleted files.

Step 3 Preview and recover files from Mac Trash
You are here now. When the scanning finishes, all files you deleted are listed with the original path, no matter you deleted them directly from Library, desktop, or Trash, etc. Undoubtedly, files you emptied from Trash are in the "Trash" folder. Or you can search the file's name in the search bar on the top to get it fast.
Before recovery, you can preview the file to make sure the files or quanlity. Common image formats, documents and archives are allowed to preview directly.

Tips:
During the scanning process, you can choose to "Pause" or "Stop" the work if you have found the files you are looking for in the list or you have to leave for a while. If you pause it, you can continue it any time when you are available. If stop, you don't need to drop the current scanning result, and you can save it on your computer for next time recovery by resuming it, which can save you much time.
Step 4: Save the recoverable files on another partition or disk
When checking the file for recovery, click on "Recover" to get them back.
What you should keep in mind is: don't save the recovered files on the same place where you lost them, in case you overwrite them. If you don't find all the files, the deleted files will be overwritten for your new files' storage.

Tips:
Before clicking on "Empty Trash", check exactly what is in the Trash Bin. If you have valuable files there, you can highlight the ones that got mistakenly sent there and drag them out of Trash Bin to avoid this data loss headache.
Chances of Mac Trash recovery
Because the operating system doesn't immediately reuse the space from deleted files, it's a plain and simple job for us to undelete trash on Mac. But the probability of recovering Trash Mac successfully decreases substantially the longer we use the computer after selecting "Empty Trash" option, because the Mac OS X may overwrite this little free space very quickly with temp files. The greatest chance of Mac trash recovery is to stop using the Mac machine once we wrongly emptied the Trash. Thus, there will be a higher chance to recover deleted Mac files after emptying Trash folder.





