Abstract: Firstly, submicron zirconia powder was dry compacted and cold isostatic pressed, and then the blocks were pre-sintered at the temperature range from 850 ℃ to 1 100 ℃. The effects of pre-sintering temperature on porosity, hardness and bending strength of the ceramics were studied. After that, milling experiment was carried out on porous zirconia ceramics, suitable pre-sintering temperature for milling porous zirconia ceramic was obtained for milling. The results show that the porosity of porous zirconia ceramics decreased, hardness and bending strength increased as the pre-sintering temperature rose from 850 ℃ to 1 000 ℃. When pre-sintering temperature was above 1 000 ℃, the ceramic particles would form sintering neck, this would greatly improve the mechanical properties of the ceramics. The suitable pre-sintering temperature for milling porous zirconia ceramics was 1 050 ℃.