Privacy is one of the important reasons why Bitcoin transactions attract users’ attention. The address generation and transaction generation of the existing Bitcoin system only rely on cryptographic algorithms and do not rely on specific organizations. There is no need for identity authentication, which better protects privacy. Existing anti-anonymity methods also mainly focus on discovering two associations: i) the association between Bitcoin addresses and ii) the association between Bitcoin addresses and specific organizations. By analyzing the network traffic that initiates Bitcoin transactions in the Bitcoin network, the relationship between Bitcoin addresses and IP addresses can be directly obtained. Our work in the paper i) obtains the traffic containing Bitcoin transactions through simple software such as wireshark, ii) finds the tx message through data cleaning, iii) obtains the input content of the Bitcoin transaction based on the specific fields in the tx message, and iv) determines input Bitcoin address of the transaction based on the on-chain information, thereby ultimately locking the relationship between the Bitcoin address and the IP address. Experimental results in this paper show that even malicious attackers using very simple network traffic monitoring tools can pose a serious threat to the privacy of Bitcoin transactions.