试一下这个patch

https://drupal.org/node/303973

或者看一下这个问题

http://stackoverflow.com/questions/4086719/how-to-highlighting-search-results-using-apache-solr-with-php-code

function THEME_apachesolr_query_alter($query) {
  // Highlight the label field
  $query->addParam('hl.fl', 'label');
}

/**
 * Implements theme_preprocess_search_result().
 */
function THEME_preprocess_search_result(&$vars) {
  if (isset($vars['result']['snippets']['label'])) {
    $vars['title'] = $vars['result']['snippets']['label'][0];
  }
  $snippet = implode(' ... ', $vars['result']['snippets']['content']) . ' ...';
  $vars['snippet'] = $snippet;
}

在主题template.php里面覆写一下搜索结果输出，适用于Drupal7