Abstract: In the social context of the rapid development of commercial cryptography industry and the increasingly urgent international environment, the society have a huge demand for cryptographic technology professionals, so it is particularly urgent to accelerate the training of high-quality cryptographic talents. Provable security as a part of the cryptography theory system, how to cryptography courses in teaching the theory of provable security is very important. This paper focuses on a kind of teaching design of provable security theory in cryptography courses through case-based teaching, aiming to improve students' in-depth understanding and practical ability of provable security. By analyzing the security of public key cryptosystems, digital signature systems, and identity-based signing schemes, this paper demonstrates how to teach the complex and abstract theory of provable security through concrete cases to ensure that students can establish an effective link between theoretical learning and practical application. In addition, the paper discusses the advantages of case-based teaching and suggests improvements to the current teaching methodology to meet the needs of the rapidly growing cryptography industry and expanding professions.