Background: Instructional design is essential for the implementation and quality of STEM education. However, it remains challenging to help teachers acquire pedagogical content knowledge and come up with novel instructional design ideas in STEM. education. Purpose: Guided by the full-perspective learning theory, this study proposed a conceptual model that was constructed by teaching needs assessment (TNA), internal meditation (IM), external interaction (EI), and idea generation in instructional design (IGID). Sample: A total of 1,727 primary school technology teachers (51.8% female, 48.2% male) who had conducted STEM learning activities participated in this study. Design and methods: Structural equation modeling was used to verify the relationships between variables. Results: The results indicated that (1) TNA, IM, and EI were positively related to IGID; and (2) both IM and EI were positively related to IGID. In addition, through the multiple group analysis, it was observed that there were significant gender differences in the idea generation process. Conclusion: The findings implied that male teachers performed better than female teachers in TNA, and were more motivated to seek ideas through IM and EI after TNA. Female teachers were more likely to obtain novel ideas through IM. The research provides some ways to facilitate the acquisition of ideas on STEM instructional design, which can be used to guide course design for instructors and course designers in STEM fields.