Cr-W pre-alloyed powders with the atomic ratio of 4:1 were prepared by mechanical milling using chromium and tungsten powder as raw material. The prepared powders were analyzed by XRD, SEM and TEM. The influence of ball milling time on morphology, microstructure and grain size of Cr-W pre-alloyed powders as well as compactness and solid solubility of the sintered Cr-W alloy were discussed. The results show that nanoscale Cr-W pre-alloyed powder can be prepared by mechanical alloying. At the initial stage of ball milling, the change of grain size and microstrain is very distinct; but it becomes a steady sate after milling for 48 h and at the same time the Cr-W pre-alloyed powders with nanocrystalline size of about 30 nm are obtained. After ball milling for 72 h, there is solid solution formed in the chromium and tungsten pre-alloyed powders. Lattice constants change during the milling process. For longer milling time of the powders, the more uniform distribution of each phase and the higher solubility are obtained after sintering