In recent years, college students began to set off an upsurge of losing weight, at the same time, "thin for beauty" of a single and deformed aesthetic concept began to invade colleges and universities. Even worse, this kind of assumption kidnaps the aesthetic assumption of college students, and has a growing trend. In order to understand the weight cognition, group characteristics and weight loss behavior of college students, especially normal students and students who are losing weight, this study adopts the questionnaire survey and interview method to investigate and analyze the weight status, cognition and behavior of college students and the factors that may affect what hold the view that. After research, the results symbolize that the Body Mass Index of college students is generally normal at present, but a considerable number of students have deviations in their weight and loses weight blindly. On the entire, there are quite a few factors affecting college students' weight cognition and this paper summarizes them into three aspects, identity background, the opinion climate and economy. Additionally there are also differences between College Students' weight perception and weight loss behavior they did.