Things You'll Need
Instructions
Insert your flash drive or external storage device into the USB slots on the PS3.
Go to the "Settings" icon and scroll down to "System Settings." Choose the "Backup Utility" option and click on "Backup."
Wait for the PS3 to detect your USB device. Once it does, select "USB Device" and press "Enter."
Scroll over to the "Game" icon on the main menu using your joystick. Choose the "Saved Data Utility" option and scroll down to the game saves you wish to back up.
Press the "Triangle" button and choose "Copy." It will give you a list of devices to transfer to; select "USB Device" and press "Enter" (X Button).
Repeat the process for every game save you wish to back up. After each backup, the "Copy completed" message will appear to verify that the backup was successful.