The 26-year-old Scot finished in 43.590 seconds, ahead of second-placed Choi Min-jeong of South Korea (43.612secs).
Christie won the event at the World Cup opener in Calgary, Canada.
She set a 500m world record in the quarter-finals at the second World Cup in Salt Lake City, USA but fell in the final.
Christie won a silver and three bronze medals at the World Championships in March and competed at the 2010 and 2014 Winter Olympics.

Owners of the company said the tough decision had been made due to falling ticket sales and high operating costs.
"As far as this great American institution, it is a sad moment," ringmaster Johnathan Lee Iverson said.
For the performers, it also means the end of a tight-knit community that lived on a train in between shows.
TAP HERE to read and watch how performers are dealing with the end of the circus.
The final performance of what the company described as "the greatest show on earth" was streamed live online.
Just before the show, David Vassallo, a clown at the travelling circus, told Reuters: "For every artist it's a dream to be part of this show, the greatest show on earth.
"I cannot even describe how happy it was for me to be part of that and I'm sad of course to wake up from this amazing dream."
Ringling Bros was the last American circus that travelled by rail.
Until Sunday, the company's train was the primary residence for most of the performers, who hail from 13 different countries.
"I learned to walk on the train, my parents were living on the train when I was born," Ivan Vargas, a sixth-generation circus performer, told the BBC earlier this month.
Vargas, 26, whose family is originally from Mexico, was born in between Sunday performances.
The final blow was delivered on 14 January 2017, late one night after the last in a "six pack" of performances in Orlando, Florida.
Posters printed in English, Portuguese, Ukrainian and Mongolian had gone up earlier in the day announcing a mysterious, mandatory all-staff meeting.
So when Feld Entertainment executives delivered the news that the circus was shutting down completely, it landed hard.
"You watched hundreds of people burst into tears at the same time," recalls ringmaster Kristen Michelle Wilson, Ringling Bros' first female ringmaster.
She had just given up her job, apartment and car to join the circus four months earlier. But the show had to go on. "The next day, we came in and did two more shows."
The five months leading up to the final performances haven't been easy.
Feld set up career counsellors at each stop. One by one, performers who found new gigs dropped off the tour.
Foreign performers without new jobs will lose their work visas shortly after the final show, and the Felds are covering plane tickets and reimbursing mileage for road trips home.
Animal rights campaigners - who had been accusing the Ringling Bros of animal abuse - have welcomed the decision to shut the company.
They held a protest in New York, carrying placards "We shut you down!" and "Bye-bye animal abusers".
British short track speed skater Elise Christie won 500m gold at the third World Cup event of the season in Shanghai, China.
[NEXT_CONCEPT]
After 146 years, America's most celebrated circus Ringling Bros and Barnum & Bailey Circus has staged its final performance in New York.