In Swedish primary schools, technology teaching may appear different depending on what educational setting the pupils meet. Many pupils experience the subject of technology as taking part in practical making-activities without recognizing the technological knowledge involved, and many teachers feel uncertain of what and how to teach technology, especially concerning sustainability. Thus, it is necessary to pinpoint these issues within teacher education. This paper presents the first iteration of a Design-Based Implementation Research (DBIR) study on a teaching module that provides student teachers with theoretical and practical knowledge in technology education. The purpose of the study is to capture and understand how student teachers transform acquired knowledge and skills into Pedagogical Content Knowledge (PCK) for teaching technology in primary school. Special attention is on how student teachers evolve relations between technology education and sustainable development. The study is designed and implemented in line with DBIR based on principles of collaboration and has strong connections between practice and theory (Fishman & Penuel, 2018). The participating researchers, also the teacher educators, have together with teachers at a municipal technological resource facility jointly identified underlying premises such as policy document statements; topics and content of value for all participants; potential participating schools; and reviews of previous research. The study includes 12 student teachers enrolled in a science and technology course. Data is collected in several steps including student teachers’ written individual reflections, their project assignments, their lesson plans, and focus group interviews. Based on qualitative content analysis, components of PCK are traced to elucidate the transformation of student teachers’ PCK for teaching technology with a sustainability edge. The results contribute to knowledge of what efforts, such as teaching module design features and connections to sustainability, should be made to develop student teachers’ PCK for teaching technology in primary school.