ABSTRACT Danggui Buxue Decoction (DBD) has shown potential antitumor effects in a variety of cancers. This study aims to delve into the effects and mechanisms of DBD on the metastasis of triple‐negative breast cancer (TNBC). The mouse model of TNBC was constructed, and the function of DBD was investigated. The active components and core targets of DBD on TNBC were identified through liquid chromatography‐mass spectrometry, network pharmacology, and molecular docking techniques. A set of in vitro experiments was conducted to examine the key components and core targets of DBD that affect the metastasis of TNBC. DBD inhibited the growth and metastasis of TNBC tumors. Formononetin is one of the key active ingredients of DBD, exerts antitumor effects by targeting Snail family transcriptional repressor 2 (SNAI2). The addition of DBD or Formononetin inhibited the malignant activity and reduced the expression of SNAI2. However, this ability of Formononetin was reversed due to the overexpression of the SNAI2 gene. Formononetin inhibits the metastasis of TNBC by downregulating SNAI2. The outcomes offer a basis for the future clinical utilization of DBD and Formononetin in TNBC therapy.