The word money laundering is literally translated from the English word "money coming", which originally meant to clean dirty money. However, the meaning of money laundering is not what it used to be, and there are various expressions. Some scholars in our country believe that money laundering refers to the act of criminals transferring, exchanging, buying financial instruments or directly investing in illegally obtained funds through banks or other financial institutions in order to compress and conceal their illegal sources and nature and legalize illegal assets. [1] Although not all crimes are for money, for many criminals, money is sometimes essential, and even some crimes are just to get a lot of money and property. In order to use the black money obtained from these crimes freely, safely and legally, criminals must try their best to launder money, and at the same time prevent investigators from investigating and collecting evidence from their "upstream crimes" in order to escape the punishment of the law.

Although it was not until 1980s that some countries defined money laundering as a crime, money laundering, a means of concealing the true source of criminal proceeds and legalizing it, has long existed. A story about the origin of money laundering vividly describes what money laundering is. In the 1920s, Chicago was founded by Ali. The financial director of an organized criminal group headed by Capone bought an automatic washing machine to wash clothes for customers, and collected cash, and then reported it to the tax authorities together with the income of other criminal organizations. In this way, the proceeds of crime become legal income. [2] With the continuous progress of science and technology, at the same time, more and more countries, especially those with more money laundering activities, make money laundering a crime and severely crack down on it, and the methods and technologies of money laundering are becoming more and more ingenious, advanced and hidden, which has caused great difficulties in identifying and cracking down on money laundering crimes.