For a long time, the American economy has dominated the world, and the US dollar has become a relatively stable international currency. The United States can pass on the economic crisis through the depreciation of the dollar. For example, in the past, 1 USD was exchanged for RMB in 7.6 yuan, but now the exchange rate is falling, and 1 USD is exchanged for RMB in 7 yuan. If the United States issued US$/kloc-US$ 0/billion of US Treasury bonds before and China bought them, it would be equivalent to 760 million RMB at that time. What about now? Due to the depreciation of the US dollar, 1 US dollar can only be exchanged for 7 yuan RMB, and 1 billion national debt is now only worth 700 million RMB. For the United States, less money is owed. In part, because of the subprime mortgage crisis, the dollar has depreciated, and many countries regard the dollar as their national foreign exchange reserves. The depreciation of the dollar has affected the import and export of these foreign exchange reserve countries, which are mainly in dollars, to varying degrees; If the dollar continues to fall, it will aggravate the global inflationary pressure and adversely affect the stability of the international financial system and global economic growth.