The disclosure provides a polysilicon etching method, including the following steps: ionizing oxygen and/or ozone and fluorine-based gas to obtain a first etching gas having a plasma state, and etching a polysilicon coated by a photoresist with the first etching gas for a preset time; and ionizing the fluorine-based gas to obtain a second etching gas having a plasma state, and etching the polysilicon by the second etching gas until the polysilicon etching is completed. The disclosure can make the line width of the polysilicon smaller, reach the requirement of the preset line width, and can improve the angle of polysilicon to make the angle of polysilicon smaller and also make the loss of polysilicon line width smaller.