The mission reliability analysis and evaluation of complex system is a very important domain of reliability engineering. Aiming at the problem of complex system mission reliability simulation, basing on multi-agent simulation modeling technology, the paper brings forward a simulation modeling method for complex system mission reliability simulation via mission profile modeling, environment profile modeling, and dynamic reliability modeling techniques. The method take into account influences of mission environment and working condition changes to the system reliability, and provides a technical approach for realizing complex system mission reliability simulation.