The issuance of new currency is the unified use of round square hole money in the whole country, and the patent of salt and iron wine is the monopoly of salt and iron wine, which is firmly controlled by the court and cannot be sold by individuals.
Qin Shihuang unified the currency mainly in the following ways: First, the state unified the coinage, severely punished private coinage, and held the manufacturing right of the currency in the hands of the state. The second is to unify the two currencies, namely, the upper currency gold and the lower currency copper.