We sought to understand better how to alleviate job burnout among grassroots civil servants. Specifically, we studied how professional group identification alleviated their sense of relative deprivation and enhanced their motivation for public service to reduce their burnout. We conducted a vignette experiment ( N = 151) and an online survey ( N = 439) on grassroots civil servants in China. In the experiment, we manipulated professional group identification to influence burnout in both experimental and control groups. In the survey, we used scales to measure the variables we were concerned about, and used the process plug-in of SPSS to analyze and compare the mediating effects. Results revealed that higher professional group identification led to lower job burnout, and public service motivation (PSM) and group relative deprivation (GRD) played mediating roles in the causal relationship. This study examined the dual pathways through which professional group identification mitigated job burnout, surpassing current understanding of the relationship between identification and job burnout. With greater validity than ever, we provide an original perspective on alleviating job burnout in public organizations.