Shuai, of China, routed fourth-seeded Carla Suarez Navarro of Spain 6-1, 6-2. Safarova, of the Czech Republic, coasted to a 6-2, 6-4 decision over countrywoman Iveta Benesova.
The championship match will be played Saturday at the West Side Tennis Club in Forest Hills, N.Y.
Shuai, 22, will be appearing in just her second WTA final. The 21-year-old Safarova will be in her sixth final. She has three WTA victories.