You win and You lose in the game.
I have played a few competition online game, and whenever the match is over,
the game rusult always says 'You win.' or 'You lose.' Is this correct?

I doubt using present tenses here is proper. I think it should be 'You won' or 'You lost'
because the match has just finished so it comes to the past.

You win / You lose VS You won / You lost
Which one do you think is correct?

Question

You win and You lose in the game.
I have played a few competition online game, and whenever the match is over,
the game rusult always says 'You win.' or 'You lose.' Is this correct?

I doubt using present tenses here is proper. I think it should be 'You won' or 'You lost'
because the match has just finished so it comes to the past.

You win / You lose   VS   You won / You lost
Which one do you think is correct?

Answer

In this case, I think it's better to use the present tense because as of that moment, the player is still in the agony of losing so he is in the present moment of "being lost" so You lose is technically acceptable. "You Lost" is also acceptable but for that particular game you're playing, it just wants to stress that you lost in the moment.