The book is slated for release November 15.
"It's a very personal book, it’s revealing, it’s been under an embargo and basically they would have to hurt you if you found it," Kelly said on her show.
According to the Radar Online excerpt, Ailes, 76, began harassing Kelly, 45, during the summer of 2005.
"I would be called into Roger’s office, he would shut the door," reads the Radar Online excerpt. "He would engage in a kind of cat-and-mouse game with me ... veering between obviously inappropriate sexually charged comments…and legitimate professional advice."
Kelly reportedly writes in "Settle For More" that she rejected "every single one" of Ailes' "physical advances," including one instance when Ailes "crossed a new line ... trying to grab me repeatedly and kiss me on the lips."
The married mother-of-three reportedly writes about her fear of speaking up about the alleged harassment. "Crossing him was a major risk,” she reportedly writes, "but what if -- God forbid -- he was still doing it to someone?”
Ailes has repeatedly denied allegations of sexual harassment.
Fox News and its parent company 21st Century Fox declined to comment.