Digital image resources are resources in which image materials are preserved through digital processing. It is presented in the form of videos and pictures, which distinctly reflect the representative image resources of each industry field. After digitalization, the image resource has the advantages of easy computer processing, easy access speed, easy remote transmission and access, easy non‐linear editing of image materials, and easy unlimited reproduction of image materials without affecting the quality of image materials. Therefore, digital image resources are widely used in various industries, and with the continuous development of social informatization, a large number of digital image resources are used in micro‐lessons to enhance the richness of micro‐lesson contents and improve the learning effect of learners. This paper reflects the design and application of digital image resources in microlearning by taking the creation of the microlearning work of "Surface Area of Rectangular and Square Bodies" in the second book of 5th grade mathematics in elementary school as an example. The paper begins with a detailed overview of the creation concept, guiding ideology and idea of the microlearning design, followed by an overview of the latest status and development of the design and application of digital image resources in microlearning, including the trends and current situation of research and creation of digital image resources in microlearning at home and abroad, as well as the elaboration of the concept of design and application of digital image resources in microlearning. Then, we analyze the innovative points and difficulties of the micro‐course "Surface Area of Rectangular and Square", which reflects the design and application of digital image resources in micro-course.