Objective To study preparation of micronized Shuanghuangpo hydrogel patch and its characteristics of transdermal penetration in vitro. Methods Micronized Shuanghuangpo hydrogel patch was prepared with some macromolecular water-soluble materials as gel base.The content of berberine was determined by HPLC method.Its transdermal penetration in vitro was determined according to the method of Chinese Pharmacopoeia 2010 edition. The rat skin penetration test in vitro was performed by modified Franz diffusion cell method. Results The hydrogel patch had constant content of berberine. Its release property in vitro conformed to Higuchi equation. The penetration of berberine in the hydrogel patch through the rat skin followed zero-order dynamics in 12 h.Its release rate was 7.934μg??(cm2)-1??h1/2 and percutaneous rate was 0.571μg??(cm2)-1??h-1. Conclusion The micronized Shuanghuangpo hydrogel patch is a new transdermal agent with sustained release property.