Reply

我三年前給哥哥一家申請親屬移民，但兩年前他住址變了，我忘了通知移民局了。

到現在我哥哥的case還沒被approved,

-It is very normal. This kind of I-130 normally takes about 4 to 5 years for approval. 

看到有人兩年就approved,是不是我犯大錯啦（沒通知地址變了）？

請老師和前輩們指教！如何通知移民局呢？不勝感激！

Do nothing now. You need to put his new address into his immigrant visa application and all related documents when NVC contact you when the I-130 priority date is current several years later.