A method of forming a photoresist layer includes: forming alignment electrodes on a base; mixing color QRs and photoresist to form a mixed material; coating the mixed material on the base; applying the base coated with the mixed material with positive and negative voltages so that the long axes of the color QRs align horizontally under the effect of the horizontal electric fields generated by the alignment electrodes; vacuum-drying the base coated with the mixed material to enhance the viscosity of the photoresist; interrupting electricity at a designated point to form a photoresist layer, wherein the long axes of QRs remain aligned horizontally; the color film substrate includes color resist films; when a backlight source emits blue light to the color film substrate, a color filter is disposed on top of the red color film to filtrate the blue light.