Hi Constance, That is actually a widely used expression in the English language and yes, it i normal for native speakers to acknowledge when they haven't seen someone for a long time. Hope this helps :)

Long time, no see. It is not Chinglish but a very common expression here in England.

As the others have said, it isn't any more. It probably once was! (as you probably know, it came from Chinese, but has now become part of English)