Background Perceived Social Support (PSS) refers to how much an individual subjectively feels cared for, assisted, and supported by others or social groups. It focuses on the individual's psychological experience and evaluation of support, rather than just the objectively existing supportive behaviors. According to signaling theory, an individual's perception of social support can act as a positive signal about oneself and the situation, aiding in the acquisition of more effective information and enhancing one's willingness and ability to adapt during career development. This paper, grounded in signaling theory, investigates how Perceived Social Support influences the mechanisms that shape an individual's employability. It also analyzes its theoretical role in this process to construct explanatory paths and research propositions.Methods This study investigates the impact mechanism of PSS on individual employability through the lens of signaling theory. A cross-sectional survey involving 534 university students in China utilized the Perceived Social Support Scale, Occupational Self-Efficacy Scale, Personal Brand Equity Scale, and Employability Scale, with structural equation modeling employed to analyze the interrelationships among these variables.Results The results reveal that: (1) Perceived social support (PSS), occupational self-efficacy (OS-E), personal brand equity (PBE), and employability are significantly and positively correlated; (2) Path analysis demonstrates that perceived social support impacts employability through the mediation of occupational self-efficacy and personal brand equity: the direct mediating effect of OS-E (indirect effect = 0.164), the direct mediating effect of PBE (indirect effect = 0.036), and their sequential mediation (indirect effect = 0.140).Conclusion This study, based on a sample of Chinese college students, reveals that perceived social support not only directly predicts employability but also indirectly influences it through a dual-mediation mechanism involving occupational self-efficacy (psychological path) and personal brand equity (behavioral path). Occupational self-efficacy serves as the foundation for accumulating personal brand equity. The findings offer empirical support from the Chinese context for signaling theory in the employment field, demonstrating that the social support system plays a role in shaping and transmitting signals. Furthermore, the study emphasizes the importance of focusing on the collaborative transformation of psychological and behavioral signals in developing employability.