The purpose of this study is to verify whether organizational fairness moderates the relationship in which workplace bullying affects job stress in social workers who have completed workplace bullying prevention education. The data from 291 respondents out of a total of 500 copies were analyzed for the moderating effect of the moderating variables by hierarchical regression analysis using the SPSS V.25 program. The analysis results are as follows. First, as workplace bullying increased, job stress increased. Second, job stress decreased as distribution fairness, procedural fairness, and opinion decision fairness increased. Third, it was confirmed that the group with low distributive fairness and opinion decision fairness moderated the effect of workplace bullying on job stress more significantly than the group with high organizational fairness. Based on this result, it was proposed to change the workplace bullying prevention education to prepare an organizational environment that can prevent workplace bullying. And practical and policy alternatives were proposed to secure distribution fairness and opinion decision fairness.