Woocommerce checkout field

Try :

add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );

function custom_override_checkout_fields( $fields ) {
   if(is_user_logged_in()){
      unset($fields['billing']['billing_email']);
   }
return $fields;
}

Source : https://docs.woocommerce.com/document/tutorial-customising-checkout-fields-using-actions-and-filters/