Here, after running Android Data Recovery, you can enter the recovery mode.
1 Connect your Android phone and enable USB debugging
2 Analyze your Android phone
After the USB debugging, reconnect your phone if you are asked to disconnect it during the setting.Here you need to bear in mind that your phone's battery is more than 20% charged, and then you can click "Start" to let the program analyze your Android phone.
3 Scan your Android
4 Preview and recover from Android
When files deleted from android, the os removes the pointer to the files from the file allocation table and flags the deleted files as no longer needed. in order to recover the deleted data with Android Data Recovery, you need to avoid writing data to the card or internal storage, plug in your device and set the usb setting as mass storage so that both the sd card and built-in storage should be recognized and mounted as removable drive, scan the drive, then recover the deleted files from android.
Check whether the phone was synchronizing with gmail/google. Search the associated Google account for any known txt message content. there may be an associated tag/metadata property identifying txt messages so you can sort them out from email.
Most SMS backup utilities in Android either back up to a file on SD card or to your gmail account as individual items.
Failing the above working, connect your Android phone to your laptop and use an Android Data Recovery program to be able to view the deleted files in the task window. After this, click on the messages that you want to recover.
More visit: How to Recover Android Messages
How to Recover Files from Android Phones