In this paper, cathode material nickel hydroxide powder of MH-Ni battery was prepared through the method of micro emulsion deepfreeze deposition with the system of Tween-80/n-C4H9OH/c-C6H12/NiSO4 solution. By measurement of the maximum content of water of different micro-emulsion system, optimum system was determined. The effect of temprature, concentration and amount of nickel sulfate solution to the particle size of the sample powder was also discussed. The structural morphology of the sample powder were analyzed and measured by XRD, SAED, SEM, TEM and particle size distribution of the sample was also analyzed. The results showed that the sample was amorphous nano-sized particles, and the size distribution was wide.