Motivation is an important factor for individuals to job choice, work behaviors and persistence. The study aims to investigate whether nonprofit organization employees will be motivated by public service motivation to maintain work engagement, and increase their well-being. The study also examines the moderation effect of person-organization value congruence. The study adopts a questionnaire survey and uses convenient sampling method from 60 nonprofit organizations in the Taipei Social Welfare Alliance. There were 133 valid questionnaires collected, and the findings of this research were as follows: (1) public service motivation was positively related to work engagement; (2) work engagement was positively related to employee well-being; (3) the relationship between public service motivation and employee well-being is completely mediated by work engagement; (4) person-organization value congruence has no significant moderating effect on public service motivation and work engagement.