Abstract: High-entropy alloys (HEA) are a new subset of metal systems with complex compositions. The inhomogeneity of the organization and properties of Al_0.1CoCrFeNi high-entropy alloy/Cu metal composite plate prepared by explosive welding and the potential mechanisms of interaction were investigated. The longitudinal periodic structural distribution as well as transverse irregular boundaries were observed at the explosive interface. By comparing the waveform parameters of the longitudinal sections, it was found that consistent waveform parameters could be obtained from different sections and measurement methods. Through the EBSD method, elongated grains were found on both sides of the wave crest and equiaxed fine grains with recrystallization in the vortex region. As the degree of grain deformation increases, the proportion of fine crystals in the corresponding regions increases. The results of nanoindentation tests showed that a periodically undulating hardness distribution along the explosion welding direction. The mixed zone was not a hard and brittle structure.