A manufacturing method of a transdermal drug delivery patch, comprising: manufacturing a master mold including a plurality of protruded portions made as a star-shaped pyramid including a plurality of protrusions extending in a radial direction; manufacturing a mold including a plurality of recess portions having a shape corresponding to a plurality of protruded portions by using the master mold; and manufacturing a transdermal drug delivery patch including a base layer and a plurality of microneedles disposed at one surface of the base layer and having a shape corresponding to a plurality of recess portions by using the mold, a drug, and a biodegradable polymer solution, characterized by the master mold including a transparent plate and the plurality of protruded portions is disposed at one surface of the transparent plate, wherein the manufacturing of the master mold includes: forming a photo-curable polymer layer on a transparent plate; disposing a grayscale mask between a light source and the transparent plate; and irradiating light to the photo-curable polymer layer through the grayscale mask to cure a part of the photo-curable polymer layer, wherein the grayscale mask includes a star-shaped light transmission part including a plurality of protrusions extending in a radial direction and a light blocking part other than the light transmission part, and a light transmission rate of the light transmission part decreases further away from the center of the light transmission part. manufacturing a master mold including a plurality of protruded portions made as a star-shaped pyramid including a plurality of protrusions extending in a radial direction; manufacturing a mold including a plurality of recess portions having a shape corresponding to a plurality of protruded portions by using the master mold; and manufacturing a transdermal drug delivery patch including a base layer and a plurality of microneedles disposed at one surface of the base layer and having a shape corresponding to a plurality of recess portions by using the mold, a drug, and a biodegradable polymer solution, characterized by the master mold including a transparent plate and the plurality of protruded portions is disposed at one surface of the transparent plate, wherein the manufacturing of the master mold includes: forming a photo-curable polymer layer on a transparent plate; disposing a grayscale mask between a light source and the transparent plate; and irradiating light to the photo-curable polymer layer through the grayscale mask to cure a part of the photo-curable polymer layer, wherein the grayscale mask includes a star-shaped light transmission part including a plurality of protrusions extending in a radial direction and a light blocking part other than the light transmission part, and a light transmission rate of the light transmission part decreases further away from the center of the light transmission part. forming a photo-curable polymer layer on a transparent plate; disposing a grayscale mask between a light source and the transparent plate; and irradiating light to the photo-curable polymer layer through the grayscale mask to cure a part of the photo-curable polymer layer, wherein the grayscale mask includes a star-shaped light transmission part including a plurality of protrusions extending in a radial direction and a light blocking part other than the light transmission part, and a light transmission rate of the light transmission part decreases further away from the center of the light transmission part.