Methods: Using orthogonal design method, to apply extract yield of Rhizoma Coptis and the extract amount of berberine hydrochloride as observing indexes, to measure the content of dl-tetrahydropalmatine with HPLC.

• 方法：采用正交设计法，以槲皮素、原儿茶醛薄层斑点，延胡索乙素含量为指标，优选提取工艺。