Public transport transfer behavior is not rare nowadays thanks to the expansion and integration of public transport systems in many megacities. Although various cities have implemented the transit transfer preferential (TTP) policy, it is still unclear what affects users’ transfer intention under the TTP policy. To understand the determinants of public transport transfer intention, we extend the theory of planned behavior (TPB) and technology acceptance model (TAM) based on 365 responses from a questionnaire survey in Xi’an, China. The multiple indicators multiple causes (MIMIC) model results show that, in addition to the typical TPB and TAM latent constructs, behavioral habit plays a critical role in public transport users’ decision to transfer. It exerts both direct and indirect effects on transfer intention. Additionally, model results demonstrate the complex mediating mechanism of attitudes, perceived usefulness, and perceived ease of use. Moreover, we find that those latent psychological constructs vary significantly across socio-economic groups and travel patterns. These findings have implications for our theoretical understanding of the drivers of public transport transfer behavior and for policymakers tasked to develop effective measures to improve the service of public transport.