In order to solve the problem of complex system reliability modeling and analysis method, a reliability modeling and analysis method based on MC (Monte-Carlo) simulation is proposed. The unit failure data samples meeting the requirements are generated, and the system-level virtual test is carried out according to the logical relationship between unit failure and system failure to obtain the system failure simulation data, and the system reliability index is obtained by statistical analysis of the system failure simulation data. The MC method is modularized by Simulink to establish a graphical reliability modeling and analysis simulation toolkit. The effectiveness of the above method is verified by various examples, and the results show that the accuracy of the system reliability modeling and analysis method based on MC simulation is equivalent to the theoretical results, and the graphical toolkit based on Simulink is realized, which is convenient for practical application in the reliability modeling and analysis of complex systems.