The protection of user privacy data in the smart home environment has become an important way to maintain and optimise the wisdom of the group in the current information age. In this paper, we propose the key technologies for smart home privacy protection from the three levels of terminal devices, data transmission interfaces and application platforms. Based on API, we propose a privacy leakage detection scheme for the smart home platform, which combines with Hook technology to obtain device privacy information and complete privacy leakage detection. Based on the improved RAPPOR algorithm, the terminal data is grouped and then executed for privacy protection. The interface data security transmission scheme is constructed based on Chaotic Logistic and RC4 stream cipher. Application practice is carried out in a living room using a smart home in District A. The accuracy rate of the privacy leakage detection technology of this paper’s platform is as high as 97.8%, and the success rate of information processing of terminals applying this paper’s terminal privacy data protection technology always maintains the level of more than 97% in different data streams downward. The authentication phase has the lowest computational overhead among all accepted data transmission confidentiality methods, with just 0.068 ms. This paper’s smart home privacy protection technology performs well in terms of effectiveness and reliability.