When you upload a photo or video, you'll have the option to turn sharing on or off for each of the social networks (like Facebook or Twitter) you want to share to. You can also share existing posts in the same manner.
See sharing to social networks to learn more.
To connect and start sharing your Instagram posts to another social network:
When viewing your own profile, select the Linked Accounts
item under the settings button in the title bar.
Toggle the social network you wish to link to and a login window will appear.
When connecting a linked account from the Upload window, the sharing option will be enabled automatically.
Business Profiles cannot be unlinked from Facebook. To link your Instagram account to a different Facebook Page for uploading and sharing, you will need to convert back to a personal profile.
To disconnect and stop sharing your Instagram posts to another social network:
When viewing your own profile, select the Linked Accounts > Social Network > Unlink
item under the settings button in the title bar.
If you're trying to relink Instagram to a social network, you may have to visit that site's settings to unlink your previous account.
Facebook: See your app settings
Twitter: See your authorized apps
Tumblr: See your Preferences and revoke access from the Applications section
To change where your posts are shared on Facebook:
When viewing the upload window, first choose your photo or video to upload, then click the Sharing
button, and select the Facebook Page (or Timeline) from the Facebook dropdown.
When viewing your own profile, select from the Linked Accounts > Facebook > Share to…
item under the settings button in the title bar.
If you have a business profile, it is not possible to change which Facebook Page your posts will share to.