Theoretically expression of Cu, Ni, W and Cu-W-Ni alloys electrodeposition possibility were thermodynamically analyzed by means of the potential-pH plots of Cu-H₂O, Ni-H₂O and W-H₂O at 25 ℃ normal temperature. It is found that Cu-Ni alloys can be deposited together in the thermodynamical stable region of the Cu-H₂O, Ni-H₂O potential-pH plots. Cu-W alloys aren’t deposited without no thermodynamical stable region of the Cu-H₂O, W-H₂O potential-pH plots, only if Cu-W-Ni induced electrodeposition under the Ni²⁺circumstances. It is possible that Ni-W alloys are prepared by the electrodeposition in the theory and experiment, which will be new method and theory for Cu-W-Ni serial contact materials’ preparation.