The assessment reliability of integrated energy systems of regional energy is an important basis for ensuring its safe and reliable operation. In this paper, a reliability assessment method of multi-component integrated energy based on Markov model is proposed. Aiming at a large number of component problems in integrated energy systems, a stochastic model based on Markov model integrated energy-energy subsystem is established. The reliability of the RBTS-Bus2 system model was evaluated and its reliability index was calculated. According to this evaluation method, it is possible to determine the proportion of demand in integrated energy systems such as photovoltaic, wind, energy storage, combined cooling heating and power and main supply, and user load. The case study shows that the integrated energy supply system can effectively improve the reliability of the system, but there are also border effect problems, which need to be further studied and solved.