When you block followers on Instagram, they no longer see your photos, videos or posts. They won't be able to find your profile using the Instagram search tool either. You can block followers only when using the Instagram app for smartphones and tablets. Accounts can't be blocked using the Web version of Instagram.
Tap the Profile icon in the bottom-right corner of the Instagram app to display your profile.
Touch Followers to load a list of Instagram users who follow your account.
Tap the account you want to block to load that account's profile.
Touch the Menu icon in the top corner of the profile page.
Tap Block User to block the user and remove him from your list of followers.