Trusova on Saturday scored 166.62 points in free program, beating her own world record and getting a combined total of 241.02 points, also the world record.
Japan's Rika Kihira won silver with 230.33 points, while South Korea's You Young got bronze with 217.49 points.
Another Russian competitor, Evgenia Medvedeva, scored 209.62 points in total and finished fifth.
Serafima Sakhanovich, the third competitor from Russia, was eighth with 175.97 points.