Privacy is a critical issue in many WSN applications because wireless sensor networks (WSNs) are vulnerable to malicious attacks due to their characteristics. Existing hop by hop and shuffling based privacy preserving protocols does not provide an energy efficient, accurate and secure data aggregation because of the energy consuming decryption at the aggregator node. How to provide effective privacy-preserving algorithm during data aggregation is important. Our main aim is to provide an energy efficient and secure data aggregation scheme, which guarantees the privacy, authenticity and freshness of individual sensed data as well as the confidentiality, accuracy and integrity of aggregated data. This paper improved on the limitations of the SMART (Slice-Mix-AggRegaTe) algorithm, and proposes a new privacy protection algorithm for wireless sensor network (WSN). We have different operations between different nodes, bring in probabilistic segmentation, and also add the data coefficient as well as the positive and negative factors. In addition we also consider making exchange time random in the algorithm. Simulation results demonstrate that the proposed algorithm reduces the communication consumption and the data traffic, improves the precision of data aggregation and the degree of privacypreserving to a certain extent.