A method of making microstructures, including: setting a photoresist layer on a base; covering the photoresist layer with a photolithography mask plate, wherein the photolithography mask plate includes: a substrate; a carbon nanotube layer on the substrate; a patterned chrome layer on the carbon nanotube layer so that the carbon nanotube layer is sandwiched between the patterned chrome layer and the substrate, wherein a first pattern of the patterned chrome layer is the same as a second pattern of the carbon nanotube layer; a cover layer on the patterned chrome layer; exposing the photoresist layer to form an exposed photoresist layer by irradiating the photoresist layer through the photolithography mask plate with ultraviolet light; and developing the exposed photoresist layer to obtain a patterned photoresist microstructures.