After the Ming Dynasty, China was in a state of trade surplus with the West for a long time, that is, there was a large trade surplus. A large amount of silver plundered by Spain in South America flowed into China in trade, which helped China establish a silver-based monetary system.

In the early Qing dynasty, the circulation of silver in the market increased greatly, which led to the higher and higher exchange rate of gold and silver. The exchange rate of gold and silver rose from about 1 8 in the 6th century (late Ming and early Qing dynasty) to 1 20 at the end of 18 (middle Qing dynasty).