Over 72 per cent of the 37,535 members - around a third of the club's overall total of members - who turned up for Saturday's referendum at the Nou Camp backed the changes being proposed, as Barca received the green light for their radical overhaul of the club's facilities.
Among the changes, Barca plan to build a new 105,000-seater stadium with a roof on the site of their current ground, which is already the largest ground in Europe with a capacity of 99,354.
The Palau Blaugrana, a 7,585-seater arena belonging to Barcelona, will also be rebuilt while the open space known as Espai Barca surrounding the Nou Camp will be redeveloped.
Other plans include an ice rink, more modern offices and 5,000 parking spaces.
Barca president Josep Maria Bartomeu hailed it as a "great day" for the Catalan giants.
He told www.fcbarcelona.com: "Days like today are when the world sees what FC Barcelona is and means.
"The support for the Nou Espai Barca proposal has been extraordinary.
"I'm very satisfied. It's a great day, a democratic festival for the Barca members. Voting made me very happy, as did seeing so many votes cast by members. It's a huge project that will improve the club for years to come."
He added: "The most important thing is that the members decide (the future of the club) in a massive way.
"The members have given me strength. We will continue to work very hard like we always have and we continue to solve problems."
In announcing their plans in January, Barca said the budget for the new project is 600 million euros (£496million) with construction work set to begin in May 2017 and conclude in February 2021.