[目的/意义]系统识别学术选题情境下用户对生成式人工智能（GenAI）的角色认知层级与演进模式，不仅有助于丰富人机协同的理论框架，也为AI4S时代GenAI的分层交互设计与学生学术创新能力培养提供参考。[方法/过程]基于计算机为社会行动者理论与角色理论框架，采用纵向解释现象学研究方法，在三个月内通过36次深度访谈，追踪了13名大学生在学术选题中与GenAI交互的行为和认知感受。[结果/结论]参考Bloom分类法，构建了包含角色类型、角色维度、具体角色及角色表现四个层级的3M角色谱系，即工具（Minion），伙伴（Mate）和顾问（Mentor）。用户对GenAI的角色认知呈现复杂多样性，GenAI的角色定位随研究进程动态演进，用户对GenAI的角色认知呈现出跃升型、扩展型和适应型三种角色动态演进模式。

[Purpose/significance] Systematically identifying the hierarchical structure and evolutionary patterns of users′ role cognition of Generative Artificial Intelligence (GenAI) in academic topic selection not only enriches the theoretical framework of human-AI collaboration but also offers implications for layered interaction design of GenAI and for cultivating students′ academic innovation capabilities in the AI for science era. [Method/process] Based on the Computers Are Social Actors theory and role theory framework, this study employed a longitudinal interpretative phenomenological analysis to track 13 university students′ interactions with GenAI and their cognitive experiences during academic topic selection over three months through 36 in-depth interviews. [Result/conclusion] This study, drawing on Bloom′s taxonomy, developed a multi-level 3M (Minion, Mate, and Mentor) role spectrum comprising four hierarchical layers of role type, role dimension, specific role, and role manifestation. Users′ role perceptions of GenAI exhibit complex diversity; GenAI′s role positioning undergoes dynamic evolution as research progresses, and users′ role perceptions of GenAI present three dynamic evolutionary patterns: elevation, expansion, and adaptation.