STEAM (Science, Technology, Engineering, Arts and Mathematics) Education has gained increasing attention over the past decade for K12 education. This article analyzes basic concepts including the principles and process of designing games. In this research, six principles in designing game structures with a STEAM approach are illustrated: purposeful, comprehensive, developmental, aligned with the structure and characteristic properties of the game, and diversified and popular. At the same time, the article outlines the step-by-step process of designing games for preschool children between 5-6 years old with the STEAM approach. Based on this, teachers will be able to design games with a STEAM approach for preschool children between 5-6 years old more efficiently and appropriately according to real-life conditions.