To address the problem that the high computational overhead of Paillier algorithm affects the real-time positioning, when it is applied to privacy protection in indoor fingerprinting, this paper proposes a privacy-preserving algorithm for indoor fingerprinting positioning of mobile users to achieve trajectory anonymity and effectively improve the positioning performance. Considering that the number of access points (APs) and reference points (RPs) involved in localization is the main factor affecting the time overhead of the encryption, the proposed algorithm divides the trajectory localization into continuous and discontinuous location localization ,The number of APs and RPs involved in encryption is reduced by using the information of the before and after requests in continuous location localization, while the number of APs and RPs involved in encryption is reduced in discontinuous location localization. In continuous position localization, the number of APs and RPs involved in the encryption operation is reduced by using the information of before and after location requests, while in discontinuous positing localization, the coarse localization of user reduces the number of APs and RPs involved in the algorithm, thus improving the location efficiency, An optional scheme based on principal component analysis (PCA) is proposed to further improve the localization efficiency. Experiments in a real-world environment show that the proposed algorithm can control the time required for a single positioning in both continuous and discontinuous positioning within 1 second, and the positioning accuracy is improved by about 20% in continuous positioning, while the privacy protection taken in discontinuous positioning has no effect on the positioning accuracy. The overall performance of the localization algorithm is effectively improved.