This study presents the design of an overseas practicum project in the early stage of preservice teacher education as a strategy to promote teacher candidates' professional development in teaching knowledge. A five-month practicum that provided both mock-up training via cloud platforms and 15-day residential experience at a Taiwanese overseas school in China was developed and implemented in 2017 and 2018. An iterative action research approach was designed with multifaceted data collection, analyses, and triangulations, to evaluate the effectiveness and student satisfaction of the programme. Results are presented and discussed following the order of programme phases to suggest the design of the overseas pre-service practicum regarding developing teaching knowledge via various phases.