Abstract: The present invention, in some embodiments thereof, provides a preparation method of a miniature solid silicon needle. The preparation method includes the following steps: growing one layer of silicon dioxide on a surface of monocrystalline silicon; depositing one layer of silicon nitride protective film on a surface of the silicon dioxide; coating a surface of the silicon nitride protective film with photoresist; and performing exposing, developing and etching, wherein the protective film adopts silicon nitride and is capable of accelerating etching reaction in the process of etching silicon, so that a diameter of a base of the silicon needle is smaller. According to the present invention, the process is simple, and the solid silicon needle has high durability and is suitable for transdermal drug permeation of biomacromolecule drugs.