Objectives In this study, we tested the mediating effect of belief in a just world in the relationship between young part-time workers' experiences of discrimination and career indecision.
 Methods An online survey was conducted targeting young people aged 15 to 34 with part-time work experience. The final 259 copies were used for statistical analysis. Descriptive statistical analysis, reliability analysis, correlation analysis, and regression analysis were performed using the SPSS 23.0 statistical program. And to verify the mediation effect, bootstrapping was performed to verify statistical significance.
 Results The average experience of discrimination was 3.06, the average career indecision was 2.32, and the average belief in a fair world was 3.77. and the average belief in a just world was 3.77. There was a positive correlation that the more discrimination experiences young part-time workers had, the higher their career indecision. There was a negative correlation between the experience of discrimination and overall belief in a just world, distributive justice belief, and procedural justice belief. It was confirmed that belief in a just world had a full mediating effect on the impact of youth discrimination experiences on career indecision. In addition, the partial mediating effect of distributive justice belief and the full mediating effect of procedural justice belief, which are subvariables of belief in a just world, were confirmed.
 Conclusions This study emphasizes the need to consider the cognitive variable of belief in a just world in the relationship between young part-time workers' experiences of discrimination and career indecision. Based on this, we laid the foundation to reduce the career indecision of young part-time workers who are experiencing discrimination and provide education and counseling opportunities to help young people enter the labor market.