Trust is often described as a “social glue” in relationships, groups, and societies, in that it connects people and facilitates thoughts, motives, and behaviors that promote collective goals. However, trusting strangers is a risky decision because we know nothing about their reputations and trusting strangers may result in betrayal. Consequently, generalized trust is an important heuristic that people use to navigate numerous daily interactions with unknown others and it is a crucial characteristic of modern societies. Previous studies suggested that social class shapes our cognition process and behavior. There also have been an emerging body of research on social class and trust, but the results are inconsistent and conflicting. In order to address mixed results in the literature, two experiments were conducted to explore the causal relationship between subjective social class and generalized trust as well as betray aversion, controlling the objective social class. In Study 1, for the purpose of testing the effects of social class on general trust, 120 participants were randomly priming with upper or lower subjective social class though a task that have been validated in advance, then they play a trust game with some strangers (Study 1a) or conduct a face trustworthiness evaluation task (Study 1b). In Study 2, 159 participants were given the same social class priming, then they conduct a minimum acceptable probability task measuring the betray aversion (Study 2). The results of Study 1a shown that compared with the upper social class priming, participants reported lower subjective social class in lower social class priming condition, indicating successful manipulation of social class priming. More importantly, the priming of the lower social class decreased the generalized trust to strangers (invested less money) in the trust game. The results of Study 1b also verified the manipulation of social class priming, and found that the priming of the lower social class reduced perceived trustworthiness to strangers in the face trustworthiness evaluation task. In addition, in Study 2 we found that there were no significant differences between risk source in upper class priming condition but in lower class priming condition. To be more specific, the priming of the lower social class increased the sensitive to social risk, in turn, increased the level of betray aversion. In conclusion, the present results indicated that lower social class priming reduced individuals’ generalized trust and increased the level of betray aversion. Our results partly support and expand the socio-cognitive theory of social class, suggesting that lower class individuals are less able to resist risks and have stronger sense of social risk, which in turn shows a lower level of general trust in order to survive and achieve life goals, while upper class individuals are less affected by the source of risk whereas they are more likely to focus on self-interests. The results of this study have important theoretical significance in revealing how social class influences generalized trust and betray aversion, and provides scientific theory reference for government and enterprises to set relevant policies and raising the level of social trust in citizens.