We choose unix c as the design tool of bank . first we analyze the development of the trade of stock online , then discuss the environment of system including telephony bank , satellite communication , the hardware of transferring system . and then elaborate on the software design . we shall resolve these problem , that is , how to use mfc to fulfill communication , how to deal with intercurrent need , how to encrypt , how to design interface statement , etc . to make the system easy to extend and integrate , some components based on com ( component object model ) are designed . the security of system is also in discuss 第一章闡述了發展網上證券業務的優勢和加強網上證券業務的安全的必要性;第二章分析了銀證轉帳系統的支持環境、系統結構模型、網絡類型和協議,并在此基礎上設計了證券交易所銀證轉帳的系統結構;論文第三章從安全、可靠、使用方便的角度上比較了windows網絡通訊的軟件設計的兩種基本方法;第四章通過系統安全性分析,給出了提高系統安全性能的解決方案。