Because RMB is subject to foreign exchange control, you can generally exchange a certain amount in the bank in accordance with state regulations when you have legitimate reasons to go abroad (such as studying abroad or traveling). If this is not the case, you can only exchange money in the black market, usually at the gate of China Bank (because of historical reasons, the foreign exchange savings of China Bank are the best in the country, so the black market of foreign exchange generally has outlets at the gate of China Bank), but you should pay attention to safety. I suggest that after negotiating the price, let the other party deposit the money in the bank first and then pay him RMB. Generally, the black market price is usually low (cost-effective). Recently, however, the international market is speculating about the appreciation of RMB, and the forward RMB is only about 1:6-7 yuan. I want to know why you want to exchange dollars.