Formal language and automata theory is an essential core course for outstanding computer workers. This course, with the characteristics of abstraction and formalization, has rigorous theoretical proofs, stronger constructiveness and the fundamental models’ establishment and their properties. To help students acquire a better understanding of the theoretical knowledge, enhance their problem-solving abilities and improve their application skills, this paper, based on a case study on fall detection and alarm systems for elderly people, introduces finite-state automata abstract definitions, thereby stimulating students’ learning enthusiasm.