The 23-year-old has been unstoppable at the final round of the season in Russia, first winning the 7.5km sprint and then repeating the trick in the 10km pursuit.
And the season closing 12.5km mass start in Khanty-Mansiysk was no different as Soukalova shot clear once again to win ahead of Marie Dorin Habert and Kaisa Makarainen.
The Czech biathlete recorded a winning time of 38:22.4minutes while a 13th-place finish from Tora Berger ensured she completed a clean sweep of World Cup titles this season.
Berger had already wrapped up the overall, sprint, pursuit, individual and, relay with her Norwegian teammates, World Cup titles and duly added the mass start to her collection.
Soukalova started slow lying down in ninth after the first shoot as Olga Vilukhina led Russian teammate Olga Zaitseva by 13.4seconds while she was only up to fifth by the second.
The lead had changed with Vita Semerenko in front of twin sister Valj with the former still the woman to beat after shooting clear once again on her third trip to the range.
Soukalova this time was second 16 seconds adrift and finally led after the fourth shoot which she shot clear to maintain a perfect record while Vita Semerenko missed one target.
The Czech held a 14.8-second lead over Dorin Habert and cruised home, slowing to celebrate her hat-trick, with the French biathlete coming home 11.2 seconds behind in total.
Makarainen held onto third, 22.9seconds behind in total, with Vilukhina fourth and Vita Semerenko fifth while Berger was 13th nearly two minutes back on Soukalova.