The integrated energy system leverages advanced information, communication, and control technology to integrate various energy subsystems, including electricity, heat, and gas, to achieve efficient and coordinated operation of the entire energy system. The integrated energy system further forms an integrated energy cyber physical system (IECPS) through resonant coupling between cyber and physical systems. However, integrating multiple energy subsystems and the deep coupling of cyber and physical procedures in the IECPS increases the risk of cyberattacks, necessitating enhanced cybersecurity measures. This paper provides a comprehensive overview of the cyber‐physical coupling modelling, security performance evaluation, attack and defence methods, and operation and recovery strategies of IECPS in response to cybersecurity threats. The coupling modelling of cyber and physical systems is discussed, followed by an evaluation of security performance of IECPS. Next, a range of attack and defence methods and effective IECPS operation and recovery strategies are presented. At last, the future research direction of IECPS cybersecurity is pointed out.