本文共分三部分:第一部分简明介绍了课题研究的背景及意义 第二部分详细阐述了无损数据压缩的原理机制和关键技术，突出强调了影响LZ77压缩效果的三要素:滑动窗口、最大匹配长度和查找策略 第三部分重占讨论了系统的设计、实现和实验数据。-This article altogether is divided three parts:The first part concisely introduced the topic research background and the significance The second part in detail elaborated does not have damages the data compression the principle machine-made and the essential technology, prominently emphasized affects the LZ77 compression effect three essential factors:Sliding window, biggest match length and search strategy The third part occupied again discussed the system design, the realization and the empirical datum.