Multi-operator wireless mesh networks (WMNs) have attracted increasingly attentions as a low-cost accessing approach for future large-scale mobile network. Security and privacy are two important objectives during the deployment of multi-operator WMNs. Despite the necessity, limited literature research takes both privacy and user experience into account. This motivates us to develop PPS, a novel privacy-preserving security scheme, for multi-operator WMNs. On one hand, most of the privacy needs are satisfied with the hybrid utilization of a tri-lateral pseudonym and a ticket based on proxy blind signature. On the other hand, the sophisticated unlinkability is implemented where mobile user is able to keep his pseudonym unchanged within the same operator in order to gain better user experience. PPS is presented as a suite of authentication and key agreement protocols built upon the proposed three-tire hierarchical network architecture. Our analysis demonstrates that PPS is secure and outperforms other proposal in terms of communication and computation overhead.