If the US debt defaults, the world economy will immediately enter the Great Depression. If the US debt ceiling is not raised and the Fed stops buying US bonds, then the US debt due will be classified as junk. At the same time, other local bonds and corporate bonds will also be downgraded, resulting in a heavier interest burden. American finance will be forced to cut spending, and high-income areas such as medical institutions and military enterprises will be significantly hit. At the same time, the rising debt cost of American enterprises will force a large number of enterprises with high assets, high liabilities and low profits to lose money or go bankrupt. In addition, the pressure of debt cost will force American capital to return and replenish the capital of domestic enterprises. When the economy is in trouble, the nature of the world economy is worse than anyone else. At present, the EU's rescue measures are not intended to change anything in essence, but are just "whitewashing" themselves. Since some American debts have become rubbish, the debts of some European countries can also become rubbish. China's foreign reserves have very little cash, and most of it consists of bonds, including about 1 trillion US bonds, Fannie Mae and Freddie Mac bonds that may exceed 400 billion, and an unknown number of European national bonds. At that time, these foreign reserves will directly become part or most of the losses due to the depreciation of bonds. At the same time, American debt and European debt become garbage, which means that the European and American economies will immediately enter the "ice bank". China's declining exports will soon come to a complete standstill. At the same time, China has more than $800 billion in foreign debt, of which more than 70% is said to be short-term foreign debt. Once the American and European economies stop, international capital will quickly return. At that time, China's foreign reserves will suffer huge losses (especially those that cannot be realized), huge international capital will be withdrawn from China, short-term foreign debts will be repaid, and domestic funds will also flee in droves, so China's nominal foreign reserves of 3.2 trillion will be exhausted in a short time. China will have no foreign exchange to buy bulk commodities such as grain, oil, iron ore, non-ferrous metals and rubber; There is no money to buy finished products, such as machinery, electronic components, chips, cars, airplanes and other luxury consumer goods. Without money to buy bulk products and key components, social activities in China will stop completely. The disappearance of China's demand will bring commodities back to historical lows, and the income of oil-producing countries such as the Middle East and Russia, as well as major mineral and food-producing countries such as Australia, Canada, Chile, Brazil and Argentina, which are rich in selling commodities, will be greatly reduced. These countries' imports from China will also disappear overnight. At the same time, Germany, Japan, France, Britain and other countries that rely on exporting products to China will also have a lot of idle production capacity, and it is difficult to recover their investment. As the center of the world economy, America's financial, IT, consumer goods, education, culture and other fields will also enter a state of atrophy. As a result, the scene in 2008 reappeared, and the situation was even worse than that in 2008. By then, non-daily necessities such as real estate, automobiles and luxury consumer goods around the world will become very worthless.