Yarnold should now secure the overall World Cup title in Königssee next week, an event which also doubles as the European Championships.
She leads nearest rival, American Noelle Pikus-Pace, who was second in Igls, by 225 points with only 225 points remaining.
Austria's Janine Flock completed the podium ahead of in-form Russian Maria Orlova while British world champion Shelley Rudman, experimenting with her equipment set-up, secured another top five ranking to continue her consistent season.
However, Rose McGrandle's bid to qualify a third British women's quota place for the Olympics is over after her 14th place in the final qualifying event.
McGrandle, who only joined the World Cup circuit earlier this year, always faced a tough battle to secure the quota slot but Germany and Russia will now have three sliders in Sochi while Great Britain, Canada, USA and Australia will be allowed two selections.
British Olympic Association officials will confirm their team for Sochi next week.
"I can't believe all the support I'm getting, I really couldn't do it without you," said Yarnold, who is seeking to defend the Olympic title won by her landlady, Amy Williams, in Sochi.
"I will just keep trying to do my best."
Yarnold's seven medals also mean she becomes the most successful British women's slider in a single World Cup season, eclipsing the six podiums previously achieved by Rudman and 2002 Olympic bronze medallist Alex Coomber.
- Sports & Recreation
- Shelley Rudman