Wave buoy has been more wildly applied in the ocean surveying field, and the bidirectional communication between the upper system and the lower system has become the focus of current researches, which transmits signal securely and effectively to upper system for reference and accurately executes commands from upper system on lower computer system,. This paper based on the GPRS wireless technology and took SCM as the core of whole system designs the lower computer system and completes the bidirectional communication. For that SCM not only sends the digital voltage data acquired and packaged after A/D conversion, but also accepts the commands from upper system to control and set the mode of current working, the bidirectional communication with wireless technology has been proposed. By system analysis on the design, this solution possesses a good feasibility, low cost, high stability and transmission efficiency, and little professional maintain.