Privacy preservation has attracted more and more attentions in wireless sensor networks. It is a challenge to provide precise Skyline query result while preserving data privacy in wireless sensor networks. This paper proposes a privacy-preserving Skyline query protocol in two-tiered sensor networks (PPSQ). Using Z-O encoding and hash-based message authentication code mechanism, this protocol to allows storage node to attain tuple relations of domination judgment without the sensory data plaintext, and therefore protects privacy of sensory data. In addition, assisted computing node calculates the verification code to ensure the integrity of the query result. Theoretical analysis and experimental results show that the PPSQ can guarantee the privacy of sensory data and the integrity of query result, and it also has better performance than the previous work in skyline query processing.