The factors restricting the development of wireless sensor networks (WSNs) included its cost, power consumption and safety. The Field Programmable Gate Array (FPGA) had many advantages with high processing speed, high frequency, low power consumption, rich IP nucleus and microprocessor. It was suitable for WSNs’ node power management and information logic control of acquisition module, storage units and transportation systems. At the same time，FPGA logic resources also used for design the system safety module. The typical chaotic system had high classic white noise and good cryptographic properties, which suited for application in WSNs’ system Security design with the advantages of simple structures and high intensity of security. Given nodes design and the chaotic encryption scheme in this paper based on FPGA Reconfigure technology.