Last year’s world vice-champion defeated Eliot Grondena of Canada, who won silver, and Omar Visintin of Italy, who won the bronze prize.
Gronden also finished behind Hemmerle in the last world championship, then coming to bronze.
Austrian Julian Leftner, who finished fourth, was left without a medal in the final.
World champion Lucas Egibars from Spain remained in seventh place this time.
At the 2018 Olympic Games in snowboarding, the French athlete Pierre Waterthe, who was also the best at the 2014 Sochi Olympics, triumphed.
The Beijing Olympics run from February 4 to 20.
