Among the victims were three children and his own children, reports ca-news.
The crime was committed in the village of Ema on September 28 last year. Yang Qingpee cracked a pick with his parents after his father refused to give him money to pay debts.
Fearing that he would be caught, Jan killed 17 fellow villagers with a pickaxe and started running in the city of Kunming, Yunan Province.
The police arrested him the next day.
Jan found guilty of murder. He asked for forgiveness from the relatives of the victims, when he was to stand trial on July 19.
He said that he will not appeal the decision of the court.