The Belarusian will face either world number one and French Open champion Iga Swiatek (21) or Jessica Pegula (28) of the United States for a place in Saturday's final.
World number six Sabalenka, also a Wimbledon semi-finalist in 2021, fired seven aces and a total of 30 winners past Pliskova, the 2016 runner-up in New York, without facing a break point.
"I expected a great level with long rallies. I wanted to stay in the match and make her work," said Sabalenka.
The 24-year-old has lost three times to Swiatek in 2022 without winning a set while holding a 3-1 career advantage over Pegula.
"They are both tough opponents. I will have to fight and do my best. I'm ready for a great battle," she added.
Sabalenka is making the most of her great escape in the second round in New York when she saved two match points against Kaia Kanepi having been a set and 1-5 down.
On Wednesday, she raced through the first set in just 28 minutes on the back of three service breaks.
The 30-year-old Pliskova managed just a single winner in the opener while serving up five double faults.
Czech world number 22 Pliskova saved two break points in the eighth game of the second set but was unable to halt Sabalenka's drive to the last four.
Swiatek is the first Polish woman to reach the last-eight in New York in the modern era and is the only player left who knows what it's like to win a major title.
The Pole has defeated Pegula twice in 2022 in her title-winning runs at Miami and Roland Garros.
Swiatek also boasts a season-leading 54 match wins this year, a stretch which has yielded six trophies.
