The new rules, dubbed "financial fair play" and due to be introduced in 2012, will in principle ban clubs from spending more than their revenue.
They are aimed at ending the trend of rich owners buying into the game and transforming the fortunes of a club.
"We don't want to kill or hurt the clubs, on the contrary we want to help them in the market," said Platini after a UEFA executive committee meeting had rubber-stamped the rules.
"That (living within your means) is the basis of accounting but it hasn't been the basis of football for years now," the former France international told reporters.
Platini said club owners themselves had asked for the reforms while UEFA's deputy general secretary Gianni Infantino said more than 50 percent of clubs were losing money.
"The teams who play in our tournaments have unanimously agreed to our principles. We don't want to prevent clubs from participating in our tournaments," said Platini.
"Our goal is not for clubs to disappear. On the contrary, we're only here to help them.
"The owners are asking for rules because they can't implement them themselves, many of them have had it with shovelling money into clubs and the more money you put into clubs, the harder it is to sell at a profit.
"I think a lot of owners would like to sell at the moment but can't because of the line of business they are in.
"The only people who want fewer rules are the ones who line their pockets," said Platini, admitting it would be a huge task to bring clubs into line and ensure the new rules were applied fairly across UEFA's 53 member associations.
"It is not easy because we have different financial systems in England, France, Germany and Georgia.
"In England you can have debts, in France you're not allowed to have debts and in Germany you get relegated to the second division (if you have debts)."
"Fifty per cent of clubs are losing money and this is an increasing trend," he said. "We needed to stop this downward spiral. They have spent more than they have earned in the past and haven't paid their debts."
