1. Illegal foreign exchange operation, under any of the following circumstances, is suspected of illegal business operation and should be filed for prosecution: 1. Buying and selling foreign exchange outside designated foreign exchange banks and China Foreign Exchange Trading Center and its sub-centers, with an amount of more than US$ 200,000, or with an illegal income of more than RMB 50,000; 2. Companies, enterprises or other units, in violation of the provisions on foreign trade agency business, fraudulently purchase foreign exchange from designated foreign exchange banks for others by illegal means, or knowingly forge or alter vouchers or commercial documents, the amount of which is more than 5 million US dollars or the illegal income is more than 500,000 yuan; 3. Buying foreign exchange by fraud through an intermediary, the amount is more than100000 USD or the illegal income is more than100000 RMB. Second, when deciding the punishment for criminals, they should be sentenced according to the facts, nature, circumstances and the degree of harm to society, in accordance with the relevant provisions of the criminal law; 3. Legal basis: Article 225 Whoever, in violation of state regulations, commits one of the following illegal business operations and disrupts the market order, if the circumstances are serious, shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention, and shall also, or shall only, be fined not less than one time but not more than five times the illegal income; If the circumstances are especially serious, he shall be sentenced to fixed-term imprisonment of not less than five years, and shall also be fined not less than one time but not more than five times his illegal income or his property shall be confiscated: (1) dealing in franchise, monopoly goods or other commodities whose business is restricted by laws and administrative regulations without permission; (2) buying and selling import and export licenses, import and export certificates of origin and other business licenses or approval documents stipulated by laws and administrative regulations; (three) without the approval of the relevant competent departments of the state, illegally engaged in securities, futures, insurance business, or illegally engaged in fund payment and settlement business; (four) other illegal business activities that seriously disrupt the market order.