How do I add body class on specific content_type who have specific field? I need to add class in body when content type article and have image on it.
How do I achieve this?

I checked in theme_preprocess_html only found content_type as string. Don't know how to check image on it.
You will need to do a little work in the html preprocess:

/**
 * Implements template_preprocess_html().
 */
function mytheme_preprocess_html(&amp;$variables) {
  $variables['has_image'] = FALSE;
  if ($variables['node_type'] == 'article' &amp;&amp; ($node = \Drupal::routeMatch()-&gt;getParameter('node')) &amp;&amp; $node instanceof \Drupal\node\NodeInterface) {
    $variables['has_image'] = empty($node-&gt;field_image-&gt;value) ? FALSE : TRUE;
  }
}


and the html template:

{#
/**
 * @file html.html.twig
 */
#}
&lt;!DOCTYPE html&gt;
&lt;html{{ html_attributes }}&gt;
  &lt;head&gt;
...
  &lt;/head&gt;
  &lt;body{{ attributes.addClass(has_image ? ['has-image']) }}&gt;


This will add the class has-image to the body tag of every Article type content node.