Concerning the interdependent network coupled by different networks, a new model for cascading failures was proposed which considered the combined effects of traffic load and interdependent edge. In the new model, the roles of interdependent edge and connected edge in interdependent networks were considered separately, variant-load global distribution principle based on the shortest path length was adopted in load allocation; the additional load assigned by the normal node was inversely proportional to the distance from the failed node. Finally, cascading failures of the interdependent network coupled by the IEEE118 standard grid network, small world network and random network were simulated. The simulation results show that the effect of global distribution of load is smaller, the failures resistance ability is stronger, the contribution of the traffic load of cascading failures is smaller and IEEE118 coupling network and the small-world coupling network have bigger failures steps when tolerance coefficient is smaller. Meanwhile, the network is unable to maintain the integrity, tolerance coefficient and failures steps appear approximately monotonically increasing relationship when the effect of global distribution of load is bigger.