Social crowding becomes a new research topic in consumer behavior domain in recent years. It is defined as the experience state caused by the large population density per unit area. At present, the research on this topic is fragmental, and the domestic research in the lens of consumer behavior is relatively rare. Therefore, it is necessary to systematically sort out relevant research. This paper firstly introduces the concept of social crowding and distinguishes the terms of density, perceived density and physical proximity. It also demonstrates the multiple measurements and manipulations of social crowding to further clarify the definition of social crowding. Then it describes the research findings from the negative and positive sides in detail. Specifically, social crowding can induce negative emotion, lead to withdraw behavior, and influence the status inference. In Contrast, some research provides empirical evidence that social crowding increases the satisfaction of experience consumption, such as consumption in the restaurant and in the bar. In addition, social crowding facilitates compensatory consumption. For example, it leads consumers to become more attached to brands as an alternative way of maintaining their basic need for belongingness. Meanwhile, this paper discusses the moderator factors of social crowding, including the view of the characteristic of the crowding component per se and the relationship between the components. For the characteristic of the crowding component, culture, gender, personality and product attributions have an impact on perceiving crowding, and as a result leading to different behaviors. The relationships between the crowding components, such as the individuals in crowding are in-group or out-group, acquaintance or strangers, also affect consumer behavior, which can be explained by the social identity theory. Moreover, this paper analyzes the mechanism of social crowding on consumer behavior from the perspective of consumers’ emotional response and cognitive processing. Based on the dual-processing model, an automatic affective process is a domain in the crowding environment, which influences consumer behavior. In view of the cognitive processing of social crowding on consumer behavior, this paper mainly discusses the control theory to explain why consumers do compensatory consumption to recover their sense of control, and the regulation theory to explain why consumers tend to be conservative in the crowding environment. In the end, it demonstrates the future research outlook in order to advance the concerns and discussion of social crowding research in domestic academia. It is divided into the implication of social crowding on marketing and the future research directions. Marketing managements should make good use of the strengths and avoid the weaknesses of social crowding. For the future research, researchers can further explore the subset of social crowding, such as well-organized or disordered social crowding, long-term or short-term social crowding. What’s more, we should explore stronger explanations for some contradictory existing findings. Finally, further research can expand the crowding background to other domains, such as health care, tourism, charitable giving, sports events, and so on. In sum, this paper reviews the influence and mechanism of social crowding on consumer behavior and points out the possible directions for further research.