Liu Xuezhou apparently took his own life in Hainan province on Monday morning, according to reports.
Mr Liu’s Weibo page has since been flooded with sympathetic comments, with many expressing anger towards the cyberbullies.
“The cyberbullying he endured was too much to bear for an adult, let alone a child,” one said.
Others said they hoped he would find a good family “in his next life”.
“I hope in your next life you find parents who protect you, brothers and sisters who love you and live a life without worries.”
His story has gripped China and prompted an outpouring of sympathy.
The 17-year-old’s story first came to national attention after he posted a video asking for help finding his biological family.
According to media reports, Liu was sold by his biological parents in 2005 and was taken in by another family.
However, his adoptive parents later died in an accident, and he spent most of his life with his grandparents and other relatives.
In December last year the 17-year-old managed to track down his birth parents, who had since divorced and remarried, after he started an online search.
Mr Liu said on social media that it had been a happy reunion at first – but things took a turn after he reportedly claimed he needed financial help.
He said he had asked his parents if he could live with them, or to buy or rent a home for him as he did not have one of his own.
However, he alleged that his parents cut him off instead, with his mother even blocking him on messaging platform WeChat.
His parents have disputed this, with his mother saying Mr Liu tried to force her into buying him a home, which she could not afford.
Mr Liu later said he would sue his birth parents for abandonment, saying in a Weibo post that he would “see them in court”.
The teenager was then reportedly cyberbullied, with many saying that he had only wanted a house from his parents and that he was trying to gain sympathy.
Just after midnight on Monday, Mr Liu posted a long essay on Weibo, in which he detailed the events of his life and how he was attacked online.
“I have endured being called many names,” he said, saying he had been effectively “abandoned twice” by his biological parents.
In the final lines of his note he said he was “ending this life of mine”. The post triggered frantic comments urging him not to take his own life, and calls for those in the nearby vicinity to find him.
His aunt later confirmed his death with local media, saying he was later found hours after the note was published and taken to a hospital where he died in the early hours of Monday.