Abstract: To cope with the emerging massive application of wireless sensor networks (WSNs) and its urgent attribute demands in low-energy consumption and high-security, a security and energy considering tree (SEC-Tree) topologized structure is proposed. Based on SEC-Tree, a multi-layer and multi-path routing protocol and a self-adaptation multi-path routing algorithm are presented. By applying pairwise shared key (PSK) in SEC-Tree initialization and route maintenance, a localized technology in encryptation and identification is brought forward to ensure the protocol high security, anti-attackability, and reliability in multi-hop and multi-path route. Theoretical analysis indicates the high efficiency and security of the routing protocol.