The invention provides a wafer cutting method. The wafer cutting method comprises the following steps: S1, providing wafers to be provided, wherein each wafer comprises a growing substrate and an epitaxial structure; S2, along cutting grooves in the wafers, carrying out cutting on the epitaxial structures from the front parts of the wafers until the growing substrates are exposed; S3, along the incisions of first cutting, carrying out second cutting on the growing substrates from the front parts of the wafers to preset depths; and S4, along the incisions of second cutting, carrying out splitting on the back parts of the wafers to complete cutting for the wafers so as to obtain single tube cores. Therefore, the occurrence of the conditions that a great deal of heat is colleted by high-powerlaser on the surfaces of wafer channels in the process that the growing substrates are cut to appointed depths once by using laser in the prior art and the distribution of heat is non-uniform and theheat dissipation is abnormal caused by the difference of all the kinds of materials of the channels so that the surface structures of the core tubes are damaged and chips are disabled is avoided.