You can sever the Pinterest link to Facebook completely or in part. Simply go to your Pinterest Edit Profile page, make the desired changes, save them, and you are done. You can choose to end sharing your pins on Facebook, or you can end the relationship entirely.
if you want to completely disconnect your Pinterest profile from your Facebook account, there's an easy way to do it.
1.ISign in to your Pinterest account using any web browser.
2.On the Home page, click your user name or the menu button (button with a pin icon) from the top-right corner.
3.From the expanded list, click the Settings option.
On the next interface, click the Social Networks category from the left pane.
4.From the right pane, under the Facebook category (category with the Facebook icon) click the Post your activity to Timeline toggle button, to set it to No. 5.Finally, click the Save Settings button from the bottom to apply changes.