It's no trouble to change 50 dollars into RMB at the bank. I need to bring my ID card. I can go to any bank with exchange business. For example, China Construction Bank, China Industrial and Commercial Bank and China Agricultural Bank can handle exchange business.

Foreign currency usually refers to the currency circulating outside the monetary system. Foreign currency exchange is a counter service for individual customers, including buying foreign currency, selling foreign currency and converting one foreign currency into another. It mainly provides services for individual customers to convert foreign exchange into RMB or other foreign currencies. Its service target is overseas individual customers.