我会根据服务器配置执行此操作。下面是.htaccess:

RewriteCond %{HTTP_HOST} !^blog\\.example\\.com$
RewriteRule (.*)\\.html$ http://blog.example.com/$1.html [L,R=301]

add_action( \'template_redirect\', \'wpse_77279_redirect\' );

function wpse_77279_redirect()
{
    if ( is_single() 
        and \'blog.example.com\' !== $_SERVER[\'HTTP_HOST\'] 
        and \'post\' === get_post_type() 
    )
    {
        wp_redirect( \'blog.example.com\' . $_SERVER[\'REQUEST_URI\'] );
        exit;
    }
}