The Italian champions paid Real Madrid £105m for Ronaldo earlier this summer and the deal will see the superstar receiving £106m over four years.
The 33-year-old Portugal captain will have his first training session with his new Juventus teammates on Monday.
And De Laurentiis has mocked the deal.
“Spending so much money to buy only one player at the end of his career is very dangerous,” De Laurentiis told La Vertia.
“Let’s remember that Cristiano Ronaldo is of a certain age and in terms of the club’s balancing of accounts, his signing is a risky move.
“The signing of Ronaldo is out of any standard.
“If you start to pay such absurd and out-of-the-ordinary salaries, sooner or later this turns against you.”
In signing Ronaldo, Juventus became the first Italian side to break the £100m barrier for an incoming transfer.