"作为评委"可以用英文表示为"as a judge"或者"as a juror".
"参加"可以用英文表示为"participate"或者"take part in".
因此，"作为评委参加"可以用英文表示为"participate as a judge"或者"take part in as a juror".
下面是一些英文例句及其中文翻译：
I will be participating as a judge in the competition. (我将作为评委参加这场比赛。)
She took part in the event as a juror. (她作为评委参加了这个活动。)