Ju, a member of the Uyghur ethnic group from the Xinjiang region in the north west of China, took the £10,000 top prize at the tournament in the Jiangsu Province near Shanghai.
Nottingham's Holt, who was the only player from outside China to make it to the quarter-finals, missed out on his third professional title having won two PTC events in recent years.
Ju, age 30, dominated the first three frames with top breaks of 58 and 55, with Holt scoring just 16 points. A run of 69 saw Holt pull one frame back and he led 37-4 in the next, but Ju battled back into the frame, then fluked the last red to a centre pocket and cleared to the pink to seal the title.
"I've been practising hard for years so I think I deserve this win," said Ju. "I wasn't feeling pressure when facing Michael Holt and I was confident. I played an open match.
"Many thanks to Mr Wang, the owner of the club I practise in, he's been supporting me all the way. I felt confident during the tournament and it seemed like I was going to get a great result here. This is my first title in a big tournament.
"I made four maximum breaks in practice before the tournament. I guess the main reason for my form could be that I do not smoke and do not drink either. I kept practising and thinking about my snooker."
Ju, who was raised by his father who sadly died six months ago, added: "I'm a farmer, I've never been to school. I loved snooker since school age and played as much as I can."
Holt said: "I'm a bit disappointed to lose but he played really well so I can't grumble. He got off to a good start and I couldn't catch him. Good luck to him, he fluked the last red but he took his chance really well.
"Obviously I was favourite, a professional is going to be favourite, but in a best of seven match, one off game, you can lose. To be fair to him, he played well. The way snooker is, if somebody plays well there's nothing you can do.
"I'm a long way from home but I do feel I get a bit of support here and I do appreciate it."
Earlier in the semi-finals, Ju beat Lu Chenwei 4-2 with a top run of 74, while Holt made a 78 in beating Liang Wenbo 4-1.
The tournament was sponsored by Zhangjiagang Guotaijiangnan Estate Co Ltd.
Ball by ball scoring and results from tournaments