Tencent helped its annual Party yesterday and invited a very popular Chinese Singer- - Zhang Liangying to sing for the party.

The news about Tencent's Annual Party and Zhang Liangying areis spreading virally online.

Although "Tencent's Annual Party" and "Zhang Liangying" are two seperate things, the thing that's spreading is the news, which is singular since it's one piece of news.

Zhang Liangying is sovery famous and popular, so her appearance fee must be very high.

"so X" as a strengthener is a very casual compared to the rest of this piece, so it doesn't fit. In a more formal piece, it makes people think of the structure "X is so Y that", and ends up sounding weird when it's used outside that context.

This exactly impliclearly showed Tencent's wealth.

"clearly showed" is a much more natural phrase

Against the backdrop of economic downturn, Tencent's revenue has maintained a growth state.

Without the has, it sounds like you're commenting on an event from the past, but I think you meant to imply that Tencent were growing and are still growing, so that's why "has maintained" is more natural here as it covers both.

Tencent helpedthrew its annual Party yesterday and invited a very popular Chinese Singer-ZhangLiangying to sing for the party.

"To throw a party" is the most common way to express this in English. Another way of saying this more formally is "to host a party". I'm sure it doesn't translate well, but it's what we all say.

The news about Tencent's Annual Party and ZhangLiangying areis spreading virally online.

"News" is treated as a singular noun in English.

This exactly impliedshows Tencent's wealth.

It has lots of famous IT products and WecChat is the most popular one.

"WeChat" is the name of a service, so it should be properly capitalised.

Tencent helped its annual Pparty yesterday and invited a very popular Chinese Ssinger- Zhang Liangying to sing for the party.

By the way, I think in English, Zhang Liangying is known as Jane Zhang.

The news about Tencent's Aannual Pparty and Zhang Liangying areis spreading virally online.

(1) "Annual party" isn't a proper noun here, so it shouldn't be capitalised.
(2) Although "news" looks like a plural noun, it's actually singular (because it's uncountable)! Hence, we use "is" instead of "are".

Zhang Liangying is so famous and popular, so her appearance fee must be very high.

This exactlyjust implieds Tencent's wealth.

Against the backdrop of economic downturn, Tencent's revenue maintained a state of growth state.

I think "state of growth" sounds more natural.