The CuCr25 alloys with high density and low oxygen content were prepared by means of vacuum induction melting. The effects of alloying elements (Ni-Al,W-Ni,W-Co) and microstructure on the physical properties and dielectric strength were investigated.The experimental results show that the chromium grains are refined when appropriate solidifying method and alloying elements are selected.On the other hand, the tungsten and cobalt serve the function of strengthening chromium phase.As a result, the dielectric strength increases notably.