In Harry Potter and the Deathly Hallows: Parts 1 & 2, and all movies, Voldemort is known to have seven horcruxes before he can die...all seven must be destroyed first.
Voldemort should know what his horcruxes are, so if he knew that Harry was one of them, then why did he kill Harry instead of keeping him alive? Assuming Voldemort wanted to live.
So harry survived the second hit, so really the horcrux being Harry should not have lived in order to kill the horcrux.
Why did Voldemort kill Harry if he knew Harry was a Horcrux?
After Voldemort split his soul six times, his soul became too unstable. When he tried to kill baby Harry, his mother sacrificed herself to save Harry, creating a shield of love for Harry.
In that situation, he can't be able to kill Harry. Voldermort's curse backfired and hurt him. He also can't be killed because he already tore his soul into six fragments. He just vanished and that unstable soul of him finds his new place in only one living thing in that room that is Harry.
So Harry is the Horcrux created by Voldemort unintentionally. So he didn't know that Harry is also a Horcrux.
Note: When Voldemort tried to kill Harry again, Harry owns the Deathly Hallows, hence he can't be killed that time. Also it affected only Voldemort's soul within Harry Potter's, so this way the last Horcrux is destroyed.
Whether he knew or not is irrelevant. He knew the prophecy said that Harry would have the power to kill him, and that is the main driving force behind his desire to kill Harry.
He knew there was some connection between him and Harry, and likely the connection was similar to Nagini. He could possess Harry (only did it very briefly at the end of #5) just as he could possess Nagini. Given that, how could he not know? He must have stopped to think about why they have that connection. Dumbledore was able to make that deduction, why can't Voldemort?
I think ultimately, he thinks he can make more Horcruxes if necessary. He doesn't know the fate of the diadem, and he believes he can protect Nagini. He only needs one horcrux, but he chooses to split his soul into 7 thinking it is lucky.
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Why is it that if Voldemort has too many horcruxes, he could die?