In order to develop a cutting fluid more suitable for β-Ga2O3 wafer slicing,the effects of different cutting fluids on the surface quality of β-Ga2O3 wafer in the process of diamond wire saw slicing were explored.The wettability of different cutting fluids on β-Ga2O3 wafer surface was studied by measuring the contact angle and surface tension.The surface of the wafer was tested and characterized using roughness measuring instrument,non-contact thickness gauge,and scanning electron microscopy (SEM),and the effects of deionized water,the water-based cutting fluid and emulsified cutting fluid with AEO-9 on the surface roughness,surface topography,total thickness variation and sub-surface damage layer depth of β-Ga2O3 (010) wafer sliced under different wire speed and feed rate were investigated.The results show that both the emulsified cutting fluid and the water-based cutting fluid can effectively reduce the contact angle and surface tension on the β-Ga2O3 surface compared to deionized water,which indicates that the lubricating capacity of both cutting fluids is improved.The effect of emulsified cutting fluid fluctuates greatly with the change of process parameters,and the wafer surface quality can be obviously optimized only under the conditions of low cutting heat and large cutting force.However,the higher wafer surface quality can be stably obtained with the water-based cutting fluid.Therefore,the water-based cutting fluid is more suitable for β-Ga2O3 single crystal slicing.