The book is a memoir by Neil Strauss, detailing his journey into the 'seduction community' and documenting his attempts at becoming the world's most successful pick-up artist.
Olly Murs, who supported One Direction on their recent US tour, introduced him to the dating guide, The Mirror reports.
A source told the newspaper: "Believe it or not, Harry hasn't always been 100% confident around the ladies. So when Olly told him about the book, he was gripped straight away and read it in a week.
"Harry has been joking that since reading it, his methods of seduction have become foolproof. His favourite tips are the ones involving talking to hot girls in group situations.
"He now knows it's actually best to ignore the women and focus his attention on the men in order to draw the girls in. Apparently, it works every time.
"But the one he has been really laughing about - and threatening to try out on the 1D lads - is the kissing technique. Harry reckons he has totally nailed it."
> James Franco in talks to play pick-up artist in 'The Game'
However, Simon Jones of Hackford Jones PR has since dismissed the reports on Twitter, writing: "Note to media, the story today about Harry Styles reading dating 'self help' book The Game is completely untrue. He has never read the book."
The One Direction star has, since the end of last year, been linked with women including Xtra Factor host Caroline Flack, Irish photographer Sarah-Louise Colivet, Bachelorette star Jillian Harris, DJ Lucy Horobin and Made in Chelsea's Caggie Dunlop.
Photo gallery - One Direction as teenagers: