The invention discloses a complex mechanism dynamic cascading reliability modeling method based on a colored stochastic Petri network. The method comprises the following five steps that firstly, a system is layered from top to bottom according to the structure, functions and operational profile of the system, the upper layer of the system is obtained by means of functional layer division, and the lower layer of the system is obtained by means of structural layer division; secondly, the fault modes and the influences of all the layers of the system are analyzed through an FMEA method, a logic relation between correlated faults is given, fault criteria influencing the functions are determined, and the hierarchy and transmissibility of the faults of the system are clarified; thirdly, a CSPN reliability submodel of each layer is established according to the logic relation between the faults and the functions; fourthly, the CSPN submodels of all the layers are connected organically by means of transition substitution to establish an overall reliability model of the system; fifthly, a color function, a node function, an arc expression function and a defense function of each layer are determined, and the reliability of the system is analyzed and evaluated by means of Monte Carlo simulation.