Interdependent networks can practically model several complex systems. In such networks, particularly critical infrastructure networks, cascading failure is the most common phenomenon observed, and hence, has gradually become a prevalent research topic in recent years. We combine statistical methods to build a cascading failure propagation model based on discrete dynamical systems. Based on a discrete-time model, a failure pattern is proposed wherein the units in a system continuously fail due to cascading events or malevolent attacks. Then, we analyze the model in combination with practical scenarios. •Risk propagation model of cascading failure based on discrete Dynamical Systems.•Conditional failure probability makes proposed model universal to practical world.•Capable of coupling multi-layer networks.•Discrete dynamic system transfers the cascade relationship on the time scale.•Propose a continuous failure pattern to simulate continuous failure events.