Nanolayered Cu-Nb composites offer a series of enhanced properties for their use in extreme conditions, e.g. high field magnets and high irradiation resistance. However, the stability of the Cu/Nb heterogeneous interface needs confirmation under various conditions. In the present work, molecular dynamics simulations were carried out to investigate the interfacial behavior under various temperatures with initial stress at the interface. It is found that the interface becomes unstable at simulation temperatures higher than 600 K, resulting in the emission of dislocations and loops within one or more slip systems. The emission process is found to be thermally-activated, i.e., the higher temperature, the shorter annealing time needed. The present study is believed to assist the experimental synthesis of the Cu-Nb multilayer nanocomposites for multiple applications. However, the stability of the Cu / Nb heterogeneous interface needs confirmation under various conditions. In the present work, molecular dynamics simulations were carried out to investigate the interfacial behavior under various temperatures with initial stress at the interface. It is found that the interface becomes unstable at simulation temperatures higher than 600 K, resulting in the emission of dislocations and loops within one or more slip systems The emission process is found to be thermally-activated, ie, the higher temperature, the shorter annealing time needed. The present study is believed to assist the experimental synthesis of the Cu-Nb multilayer nanocomposites for multiple applications.