With the ubiquity of information technologies (IT) such as phones, emails, and instant communication media, employees frequently receive work-related interruptions during non-work time. Sometimes, the interruptions can be excessive for individuals to handle, which impose significant consequences on their personal life. Drawing on conservation of resources (COR) theory, we examine IT-mediated work-related after-hours interruption overload on work-life conflict. We predict that after-hours interruption overload causes work-life conflict through the mechanism of psychological transition. Further, preemptive processing method will positively moderate the mediation relationship while sequential method will negatively moderate it. Empirical evidence is based on two time-lagged surveys from a final sample of 336 full-time employees. Our study extends the research focus to work-related interruptions during non-work time and add knowledge to the mechanism and boundary conditions of after-hours interruption overload.