本文从投资者群体感知度的视角,在放松投资者理性的框架下,通过建立投资博弈的认知层次模型,系统地揭示了群体感知度在投资博弈结果形成中的作用机理.研究表明:即使在投资者是有限理性的假设下也应当出现纳什均衡预测的适度投资,而投资总体的群体感知度偏差将使得合理的市场投资规模产生偏离,正是投资者对于参与投资者总体的分布产生的群体感知度偏大导致了投资的过度,偏小则不足,一个简单的实验也初步检验证实这一结论.文中最后也针对现实经济中存在的投资过度现象,从投资者群体感知度的角度简要分析了几点成因.“,”From the perspective of investor's group perception, this paper works out an investment game model based on cognitive hierarchy under the framework of bounded rationality, in order to explain the mechanism of group perception how to form investment game results. The study shows that the moderate invest- ment will be the prediction of Nash equilibrium even if we release the perfective rationality, and the bias of group perception can cause inconsistency. A brief experiment also gives a preliminary test. The paper also explores the reason of excessive investment in economy through analyzing group perception of investors.