This study examines a curvilinear relationship between job insecurity and unsafe behaviour among coal miners. Drawing from conservation of resources theory, we develop and investigate an explanation for coal miners’ reactions to job insecurity based on their allocation of psychological resources at different levels of job insecurity. By using three-wave longitudinal data from 209 coal miners in northern China, we find support for the U-shaped relationship between job insecurity and unsafe behaviour. That is, coal miners' unsafe behaviour gradually decreases when they perceive a level of insecurity in their jobs, but beyond a certain point, their unsafe behaviour increases. Furthermore, we find that psychological detachment, but not self-control, moderates the curvilinear relationship, such that coal miners with higher psychological detachment exhibit less unsafe behaviours. We also discuss the theoretical implications of this study on job insecurity and unsafe behaviours, and the practical implications for organisations in the coal mining industry."