Training functional living skills is crucial for students with intellectual and developmental disabilities (IDDs) because they are directly related to their independence. The aim of this study was to explore the effect of an augmented reality (AR)-based video prompting (VP) teaching model on the learning of functional living skills among elementary school students with intellectual and developmental disabilities. A multiple-probe, across-subjects, single-case research design was adopted to recruit three participants, namely, fifth- and sixth-grade students with IDDs in a special education program in an elementary school in Taichung City. The independent variable was the AR-based VP teaching model, and the dependent variable was the participants' performance of functional living skills (cooking rice in a rice cooker). The results indicate that the intervention had immediate, maintenance, and generalization effects on all three participants. In addition, the participants noted that the teaching model relaxed and motivated them. The teachers also indicated that the teaching model motivated the students, resulted in positive learning outcomes, and strengthened the students' ability to learn independently. Through this AR-based VP teaching model, students with developmental disabilities can improve their functional living skills.