Kai Zhuang was discovered “very cold and scared” in a tent in rural Utah, Riverdale Police said in a statement.
The 17-year-old is believed to have isolated himself after being manipulated by the kidnappers.
His parents were then tricked into paying around $80,000 (£62,600).
Zhuang is one of a number of foreign students targeted by so-called cyber kidnappers in the US recently, Riverdale Police added in their statement.
Police believe Kai was being controlled by the kidnappers as early as 20 December, when he was seen by officers in Provo, Utah, carrying camping equipment.
Those officers arranged for him to be returned to Riverdale – where he lived with a host family – out of concerns for his safety. He did not mention any threats at the time, however.
Police were then contacted on 28 December by the school he was attending, which had been contacted by his parents in China.
Kai’s parents had told school officials they had been sent a ransom demand and a picture of their son indicating he was abducted.
According to police, victims of cyber kidnapping are convinced to isolate themselves, and even take pictures to make it appear they are being held captive – despite the kidnappers not being present. Instead, the victim is monitored through Facetime or Skype.
Both the victim and their families are then convinced the other will be harmed if they do not comply.
But despite the kidnappers not being with Kai, police in Utah still feared for his safety, explaining the state’s December temperatures meant there was a risk he could “freeze to death overnight”.
Kai was eventually found around 25 miles (40km) north of Riverdale, near Brigham City, in a tent with “no heat source” on Sunday.
He had limited food and water, a heat blanket and a sleeping bag – as well as several phones which police suspect were used to carry out the kidnapping.
Following his rescue, Kai, who had been checked for hypothermia, requested a “warm cheeseburger” and to speak with his family.
