PurposeThis study aims to examine how Chinese rural-urban migrant workers' socio-economic status was associated with their decent work.Design/methodology/approachGrounded in the psychology of working theory (PWT), this study tested the path from rural-urban migrant workers' socio-economic status to decent work via work volition, with this path moderated by environmental uncertainty and trade union support. 470 rural-urban migrant workers from four manufacturing enterprises were investigated.FindingsResults indicated that rural-urban migrant workers' socio-economic status was positively associated with rural-urban migrant workers' decent work through work volition. In addition, environmental uncertainty weakened the impact of socio-economic status on work volition while trade union support strengthened the relationship between socio-economic status and work volition.Originality/valueThe study contributes to the growing research on the PWT by testing its utility among rural-urban migrant workers in the Chinese context. The study also identifies the crucial effects of environmental uncertainty and trade union support, which are distinctive characters of contemporary China, in the formation process of rural-urban migrant workers' decent work. A detailed explanation of the results and implications is discussed in the end.