To explore the effective components of Guishao Yigong decoction (GYD) in the treatment of colorectal cancer and reveal its potential mechanism of action. Through network pharmacology, the main target and signaling pathway of GYD therapy for colorectal cancer (CRC) were found. Subsequently, the effect of GYD was verified by in vitro cell viability measurements, colony formation, and scratch healing tests. The effects of GYD on metabolic pathways in vivo were found through plasma metabolomics. Finally, flow cytometry and qPCR experiments were used to verify the cycle-blocking effect of GYD on CRC cells. Based on the network pharmacological analysis and molecular docking technology, it was found that GYD could restrain the growth of CRC cells by affecting lipid metabolic pathways and mitogen-activated protein kinase (MAPK) signaling pathways. A series of cell experiments showed that GYD could inhibit the proliferation, migration and clonogenic ability of CRC cells. Furthermore, the plasma metabolomics results showed that GYD could affect the production of unsaturated fatty acids in mice. Flow cytometry and qPCR experiments further proved that GYD blocked the CRC cells in the G1 phase and modulated the expression of cell cycle-related targets, such as AKT, TP53, CDKN1A, and CDK2. All the results indicated that GYD could regulate the related metabolism of unsaturated fatty acids. Thus, the cell cycle was blocked and the expressions of the key proteins such as AKT and TP53 were regulated, which achieved the purpose of intervention in colorectal cancer.