The movement of glide dislocations in Cu/Ni films during nano indentation and friction was simulated by using 3D and 2D molecular dynamics methods respectively, and the interactions between interface and glide dislocations were analyzed. The results show that the repulsive force produced by the misfit dislocation network at the interface prevents the glide dislocations accessing or passing through the interfaces; the image force arising from the modulus difference across an interface confines the glide dislocations to move within Cu individual layer. Both of the above forces can be used to explain the strengthening mechanism of Cu/Ni multilayers.