Abstract: Based on the Holland occupational classification and situational judgment tests, taking Holland’s enterprising jobs as an example, a new vocational aptitude assessment tool was developed. A mediation model was developed and tested, which demonstrates the indirect effects of vocational aptitude on task performance via person-job fit and work engagement, and the moderating effects of person-group fit. Data from 471 effective samples was used to conduct an empirical analysis. The results revealed that: ①vocational aptitude exerts a significantly positive effect on task performance; ②vocational aptitude has an indirect effect on task performance through person-job fit and work engagement, respectively; ③person-job fit and work engagement play significantly as serial mediators between vocational aptitude and task performance;④the examined mediating effects are moderated by person-group fit.