The Dane, who has never appeared in the Miami final, will play the winner of Thursday's later semi-final between a resurgent Venus Williams of the United States and Britain's Johanna Konta.
Pliskova, who has won titles this year at Doha and Brisbane, also fell at the semi-final stage in Indian Wells two weeks ago but started the early afternoon contest in positive fashion.
The Czech broke Wozniacki in the first game of the match but the Dane fought back and at 5-4 had three set points, which Pliskova manage to deny her.
Wozniacki then double faulted to give the Czech a break point, which she took before serving out for the set.
But former world number one Wozniacki, wearing down Pliskova with her solid defense, ran out a comfortable winner in the following two sets to earn a third final appearance of the year.
"I'm not sure how I managed to do that," Wozniacki said. "It is tough when you lose that first set -- especially having set points, it hits you a little bit. But I got a good start to the second set and that got me going, got me grinding."
In her two finals this year, both in February, Wozniacki was beaten by Pliskova at Doha and by Ukrainian Elina Svitolina at Dubai.
Pliskova, who began the year with a title at Brisbane, was philosophical about her second semi-final loss of the month.
"I'm definitely positive," she said. "I've won a lot of matches this year. I can't be too disappointed but obviously I am disappointed to lose two semi-finals especially when I think I could have won both matches.
"Obviously I think I could have done a bit more this year but then again I have never had a start to a season like this."