The 22-year-old triumphed in a giant slalom in Courchevel, France Tuesday to add to a slalom and a debut downhill victory
already this term.
The defending World Cup overall champion beat France's Tessa Worley over two runs in sparkling conditions in the French Alps with Italy's Manuela Moelgg third.
Shiffrin led after the first run on the Emile Allais piste and held on to her advantage to record a 34th World Cup win, the same number as Norway's Aksel Lund Svindal and one more than fellow American Bode Miller.
Shiffrin leads the World Cup overall standings from Germany's Viktoria Rebensburg with Liechtenstein's Tina Weirather in third.
However, she denies her impressive start to an Olympic season heaps pressure on her to perform in South Korea.
"If people think I can win a couple of medals that's actually just a a compliment," she told reporters in Courchevel.
"It's not really pressure to do it -- I don't have to do it, I don't even have to go to the Olympics but I'd go because I want to.
"It's an incredible stage to perform on and because I want to share my passion for ski racing with the world, so I take it as an opportunity not as pressure."
Compatriot Lindsey Vonn, who won a super-G in nearby Val d'Isere Saturday, was quick to applaud Shiffrin.
"Congrats @MikaelaShiffrin and impressive 2nd run @TessaWorley. Manu [Moelgg] keeping it real for the old ladies."
Shiffrin recently told CNN's Alpine Edge she was "scared" by the ramifications of Russia's state-sponsored doping program
before and during the 2014 Sochi Winter Olympics.
As part of the deception, Russia developed a way of breaking into "tamper-proof" bottles and replacing tainted urine samples with clean ones so that dopers passed drugs tests.
"The most concerning thing for me is that, in my opinion, it would be much easier to make a clean sample look dirty; than a dirty sample look clean," Shiffrin told Alpine Edge's Christina Macfarlane.
The Vail native made her World Cup debut at the age of 15 and became the youngest Olympic slalom champion when she triumphed in Sochi, aged 18 years 345 days.
Shiffrin won slalom gold at the last three World Championships stretching back to 2013, and was also second in the giant slalom at the last worlds in St. Moritz, Switzerland in March 2017.