Fifty handwritten pages, which Prince submitted a month before his death, will form the basis of the book, which has been “newly envisioned” as a scrapbook of his life.
It will also include rare photographs and handwritten lyrics, alongside the original draft script for Purple Rain.
Publishers Random House said the book was “deeply personal”.
Prince, who died in April 2016 from an accidental overdose of the pain medication fentanyl, was one of the “big three” superstars of the 1980s, alongside Madonna and Michael Jackson.
He was purposefully inscrutable, rarely giving interviews and building his own mythology through music. But in the year before his death, he had started to let his guard down, reflecting on his life and career during a solo tour titled Prince: Piano & A Microphone.
Those concerts appeared to inspire the idea of a memoir, which Prince announced at a private show in Manhattan in 2016.