Abstract: In order to assess the performance reliability of dynamic and multi-state avionics computing platform, "serial gate", "parallel gate", "condition gate", "multi-state cold spare gate" are propesed and a multi-state dynamic fault tree analysis methord is designed for multi-state system analysis. A multi-state dynamic fault tree of representative structure avionics computing platform is constructed using the dynamic fault tree analysis methord and calculated by Mento Carlo simulation.The multi-state dynamic fault tree analysis methord can evaluate performance reliability of avionics computing platform under different performance requirements, and can provide theoretical data for reliability design of avionics computing platform.