Bitcoin mixing operations are commonly used to enhance transaction privacy by obscuring the connection between inputs and outputs. However, current methods have drawbacks such as relying on trusted third parties, being susceptible to rogue key attacks, and inefficiency. To tackle these issues, our paper introduces a decentralized Bitcoin mixing scheme CoinMixMultiSig (CMMS), which enables participants to collaborate in generating a public address. This scheme employs a two-round public address generation process, wherein all participants send bitcoins to the jointly generated addresses before signing them to prevent fraud. Additionally, CMMS utilizes a multi-signature mechanism that not only reduces the size of signatures but also significantly improves the system’s scalability.