First, choose a password that is difficult to guess yet easy to remember.
Next, since your email address doubles as your Facebook username, change your privacy settings to hide your login email address from your public profile:
1 – Log in to your Facebook account and visit your About page.
2 – In the left-hand column, click Contact and Basic Info.
3 – Hover your mouse over the Email field, then click the Edit button after it pops up.
4 – Click the Lock icon beside the email address that you use to log in to Facebook, then select Only Me.
5 – Next, click the down arrow on the far right and select Hidden from Timeline.
6 – Repeat steps 4 and 5 for any other email addresses that you wish to hide.
Now that you have hidden your log in email address and selected an unbreakable password, you have the opportunity to use your cell phone as a fool-proof “lock” on your account. Here’s how:
1 – Click the down arrow that’s located in the upper right-hand corner of the screen.
2 – Click Settings.
3 – Click the Security link in the left-hand column.
4 – Click on Login Approvals.
5 – Check the box beside Require a security code to access my account from unknown browsers.
6 – Enter your phone number in the Security code delivery section.
7 – Click Save Changes.
From now on, any time you (or someone else) tries to log in to your Facebook account from an unknown device/browser, you’ll receive a text message on your cell phone with a security code that you must enter before Facebook will allow you to log in. This means it will be impossible for someone else to log in to your Facebook account from a device that you do not own unless they also have physical access to your cell phone.
That’s all there is to locking down your Facebook account to prevent hackers from taking control of it.