According to Zhu Min, deputy managing director of the International Monetary Fund, China's capacity utilization rate was down from 90 percent to 60 percent, and overcapacity has become a major threat to the country's position on the global value chain.
Facing the challenges, Lou said fiscal expenditure must have a "bottom line", and priorities must be given to what is important, as too many commitments will strain revenue and "lead us to a dead end".
Lou said the low price of energy in China was a major reason for energy waste.
Carbon tax levies could come under consideration, he said.
He also said many of the policies on improving the standard of living lacked prerequisites.
"We should help the poor, but not the lazy," he said.
Meanwhile, the former head of China's wealth fund did not agree with the idea of using the country's $3 trillion foreign exchange reserve to compensate social security, as it was "too risky".
"If the loopholes in the social security system are not closed, there will never be too much money to be wasted," he pointed out.
Lou said he was heading an investigation on the 11-trillion-yuan local government debt to separate hidden debts from those on the balance sheet.
In addition, he said, a larger proportion of profits of the State-owned enterprises will be collected.
"Hopefully, when these efforts are made and the external environment improves, we can return to a fiscal balance," Lou said.
Lou's views were echoed by Martin Wolf, chief economic commentator for the Financial Times, who said "the low growth rate and high deficit level which the United States and Europe are currently undergoing may not be the recipe for China''.
Angel Gurria, secretary-general of the Organization for Economic Cooperation and Development, said the major challenge for any fiscal reform is lack of revenue, but China has been doing well considering the relatively low debt-to-GDP ratio and fiscal deficit level.
In order to gain more fiscal revenue, the first step for China to take should be to broaden its tax base, according to Stephen Groff, vice-president of the Asian Development Bank.
In addition, direct tax items, such as capital gains, property, inheritance, and an environment tax, should play a bigger role in easing the pressure of falling revenue, he said.
Gurria estimated the real burden for Chinese taxpayers was 29 percent of their income. The level has been growing annually 0.5 percentage points over the past five years, he said.
Top 10 richest people in Beijing 2013: Hurun