分析和对比了哈希函数在信息安全、数据结构和数据挖掘等领域的应用，找出了它在不同领域里所呈现的特点和要求：信息安全领域里的单向性、随机性和无碰撞性，数据结构里尽可能减少碰撞、但不能避免碰撞，而数据挖掘里用于任务分配时则要求均匀碰撞。这为相关课程的学习提供了一些有益的参考，便于澄清一些模糊、混淆的认识。(Analysis and comparison of the application of hash function in information security, data structure and data mining, to find out the features and requirements of it in different areas in the field of information security in one-way, random and collision free, data structure as much as possible to reduce the collision, but the collision cannot be avoided, and the data mining for task allocation is uniform requirement of collision. This provides some useful reference for the study of the related courses so as to clarify some vague and confusing knowledge.)