.go on business是继续工作和出差的两重意思,be away on business 是出差,出去做生意的意思.
例句：
Welcome to beautiful China - Qingdao go sightseeing or go on business and handle affairs,stay where I offer.
欢迎你到美丽的中国-青岛观光旅游或出差办事,并下榻我舍.
After being away on business,Tim thought it would be nice to bring his wife a little gift.
做完生意回来后,提姆觉得应该给妻子带点什么礼物回去.
在表示出差的时候,第一个是去出差的意思,第二个是正在出差的意思.
例如：i’ll go on business.我要出差了.
i am away on business.我正出差呢!
很大程度上,在表出差的时候,两个词其实是可以混用的,但在表其他意思的时候就不可以.