Abstract: The implementation plan of a Browser Helper Object（BHO） based website filtering system is proposed in this paper by using the technologies of web filtering，anti-destruction and keyboard monitoring.The details of the sensitive image detection mechanism embedded in the web filtering technology are introduced emphatically，where a flexible and strict filtering system and an online environment with reliability and security are available owing to the triple filtering method：URL filtering，text filtering and sensitive image filtering.The results of experiments verify the effectiveness of the proposed system.

Key words: website filtering, sensitive image detection, Browser Helper Object（BHO）

摘要： 该文利用浏览器助手对象（BHO）插件技术，提出了网站过滤系统的系统结构设计和功能模块设计方案，并对网站过滤系统的过滤技术、反破坏技术和键盘监控等关键技术进行研究，重点讨论了敏感图像检测技术。系统使用网址过滤、文本内容过滤和敏感图像过滤等三重过滤机制，可为用户提供可靠安全的上网环境。实验结果验证了该系统的有效性。

关键词: 网站过滤, 敏感图像检测, 浏览器助手对象