Still can't play Battlefield 4 after purchased premium edition code

Did you purchase "premium edition" or "premium membership"?  You said you downloaded, does the game show up in origin for you?

It's Premium membership

That is not the game.  You bought the addons. You will need to buy the game to play it. 

Premium membership only gives you access to the DLC's and premium features.  You still have to buy the base game in order to play.  This seems to be your issue.  "Premium Edition" would have given you both the game and the membership.

So how to buy the game? Which one is the game? Thank you

This is the base game which is what you need:

https://www.origin.com/en-us/store/buy/battlefield-4/pc-download/base-game/standard-edition

This is the "Premium Edition" which is probably what you meant to buy:

https://www.origin.com/en-us/store/buy/battlefield-4/pc-download/base-game/premium-edition

This is the "Premium membership" which is what you actually bought:

https://www.origin.com/en-us/store/buy/battlefield-4/pc-download/addon/battlefield-4-premium

Thank you

So i need to buy one more step

Yes,  since you bought premium membership, buy this:

https://www.origin.com/en-us/store/buy/battlefield-4/pc-download/base-game/standard-edition