Wireless transmission method in wireless sensor networks has put forward higher requirements for private protection technology. According to the packet loss prob-lem of private protection algorithm based on slice technology, this paper proposes the data private protection algorithm with redundancy mechanism, which ensures privacy by privacy homomorphism mechanism and guarantees re-dundancy by carrying hidden data. Moreover, it selects the routing tree generated by CTP (Collection Tree Protocol) as routing path for data transmission. By dividing at the source node, it adds the hidden information and also the privacy homomorphism. At the same time, the information feedback tree is established between the destination node and the source node. In addition, the destination node im-mediately sends the packet loss information and the encryption key via the information feedback tree to the source node. As a result, it improves the reliability and privacy of data transmission and ensures the data redundancy.