In summary, the aqueous tape casting method was used to prepare YAG composite structure ceramics with high optical quality. The average grain size of the YAG ceramics sintered at 1750 °C for 10 h is about 15 μm. The inline transmittance of the sample is 81.5% at 1064 nm. The results indicate that the aqueous tape casting method is a promising technology for preparing transparent ceramics. By using this technology, laser ceramics with composite structures can be obtained. Recently, Nd:YAG and Yb:YAG composite ceramics are being developed in our group. The information of the new works will be reported soon.