The Beijing Chainan Chainsmap monitoring system analyzed the relevant information disclosed by the U.S. Treasury Department and sanctioned bitcoin OTC exchangers, and found that the money laundering in the related cases mainly began in June 2018. A 3800 bitcoin transaction was related to money laundering At least one starting point of the event, and subsequent continuous transfers, in the process, the relevant top-up addresses in the exchanges such as coincola, LocalBitcoins, etc. were stripped in units of dozens of BTC, and these addresses have been disclosed in the official information disclosed by the United States. According to data analyst SXWK, we also found that the transaction that brought together the first huge bitcoins originated from the HitBTC exchange. These transactions were collected from June 25 to July 5, 2018, and prepared for the subsequent money laundering. In view of the previous theft of various digital currencies by related hacking organizations, we also do not rule out that they first exchanged with Bitcoin on some exchanges, and then carried out subsequent money laundering. This also fully shows that the current money laundering behavior based on digital currencies is already a professional work across currencies and exchanges, and the industry urgently needs professional anti-money laundering technical support and joint defense mechanisms.