Abstract: The preparation technology of low-hydrated zinc borate(2ZnO·3B↓2O↓3·3.5H↓2O) by microwave heating with borax and zinc sulfate as raw materials was studied.The effects of reaction temperature，liquid-to-solid ratio，microwave radiation time，microwave power etc.on zinc borate productive rate and particle size distribution were investigated and the optimum process condition was confirmed through optimized experiments.Experimental results showed that low-hydrated zinc borate whose average particle diameter is 10.16 μm can be prepared under condition of reaction temperature proper 85 ℃，liquid-to-solid ratio 3∶1，microwave radiation time 50 min，microwave power 630 W，and the productive rate has reached 99.18%.At the same time，characterization of product adopting XRD diffraction and thermogravimetric analysis was carried out and the spectrogram of XRD diffraction diagram accorded with the standard spectrogram of low-hydrated zinc borate；it is indicated that product dehydration temperature approached theory dehydration temperature of low-hydrated zinc borate by thermogravimetric analysis. <DIV>&nbsp;</DIV>