A layer of W skeleton with 100-200μm was obtained by corroding the Cu of CuW surface. Then, a porous structure diffusion barrier layer was formed by electroless Ni plating on W skeleton. Finally, the CuW/Al bimetals was prepared by using solid-liquid connection at 700℃. The microstructure of interfacial diffusion layer at different holding time was investigated, and the precipitation sequence of the intermetallic compounds was analyzed. The results show that the porous structure Ni interlayer between CuW/Al interface can effectively reduce the amount of Al2Cu compounds, and prevent the formation of Kirkendall voids. The CuW/Al interface mainly consists of Al2Cu and Al5W phases. By adding porous structure Ni interlayer, the interface bonding property and electrical conductivity of CuW/Al were improved.