Using the Baoxi clay which was strenthened by Al2O3 as the main materials. And then import the ZrO2(Y2O3) powder that made by the sol-gel method. Studied the microstructure and mechanical properties by the addition of the ZrO2(Y2O3) . The result shows that, with the increasing of ZrO2(Y2O3) content the body strength improves at first but declines afterward . While the content of ZrO2(Y2O3)was 2% in the Baoxi clay with 22%α-Al2O3, the sample shown the max bending strength and most compact volume density. The strengthen mechanism was stress-induced transformation toughening.