Risks and resulting propagating accidents pose considerable threats to the stability of project portfolio network (PPN). To maintain PPN stability, a PPN risk propagation model considering risk perception is constructed. First, a PPN is developed to concurrently visualize the risk propagation paths and the risk perception diffusion paths. Second, modifications to the disaster spreading model are made to construct the PPN risk propagation model supporting more realistic simulations. The model is then applied to numerical simulations, yielding risk propagation mitigation measures. The results suggest that risk mitigation is facilitated by increased trust among project managers, moderate differences in initial project manager risk perceptions, a homogeneous PPN topology, and a tendency to allocate recovery resources based on node degree centrality. These findings guide enterprise administrators in risk decision-making, contributing to stable PPN operations.