function remove_more_jump_link($link) {
    $offset = strpos($link, '#more-');
    if ($offset) {
        $end = strpos($link, '"',$offset);
    }
    if ($end) {
        $link = substr_replace($link, '', $offset, $end-$offset);
    }
    return $link;
}
add_filter('the_content_more_link', 'remove_more_jump_link');

或者

function remove_more_jump_link($link) {
return preg_replace('/#more-\d+/i','',$link);
}
add_filter('the_content_more_link', 'remove_more_jump_link');