This paper proposes a new scheme design and hardware implementation of wireless transmission system based on FPGA and chaotic encryption with A5/1 algorithm. This design uses FPGA chip as the encryption core, in which Logistic system generates the initial key and encrypts the plaintext combined with A5/1 algorithm, then it uses SIM300 module to realize wireless transmission. Develop two test boards to get hardware implementation of this design scheme, which can simulate wireless transmission of text messages and transfer data to the third one to verify its security of encrypted information. In this paper, it mainly introduces the overall design and the hardware encryption scheme of this FPGA & chaotic encryption-based wireless transmission system, and finally it shows hardware test boards and part of the test results which can confirm the feasibility of this design scheme.