Colorectal cancer (CRC) exhibits high incidence and mortality rates, and current therapeutic approaches remain limited, underscoring the urgent need for novel treatment strategies. Astragali Radix, a traditional Chinese medicine with diverse pharmacological properties, has shown potential in cancer therapy; however, its anti-CRC mechanisms remain poorly understood. This study investigated the active components of A. Radix and their anti-CRC mechanisms using an integrated approach combining network pharmacology, molecular docking, and in vitro and in vivo experiments. Twenty active components of A. Radix with high oral bioavailability and drug-likeness were screened from databases, and relevant networks were constructed to identify core targets, including SRC, PIK3CA, and AKT1. Enrichment analysis revealed that these targets are primarily involved in the regulation of the PI3K-Akt signaling pathway. Molecular docking confirmed strong binding affinity between the active components of A. Radix and the core targets. In vitro experiments on HCT 116 and HT 29 cells demonstrated that A. Radix and quercetin inhibited cell proliferation in a concentration- and time-dependent manner, downregulating the mRNA expression of key genes (PIK3CA, PIK3R1, AKT1) in the PI3K-Akt pathway, and A. Radix showed superior efficacy compared with quercetin. Western blot analysis confirmed that the protein levels of PI3K, p-PI3K, AKT, p-AKT, PIK3CA, PIK3R1, and AKT1 were reduced in A. Radix-treated cells, as were the ratios of p-PI3K/PI3K and p-AKT/AKT. In vivo experiments on MC38 tumor-bearing mice further revealed that A. Radix significantly suppressed tumor growth and reduced pathway-related protein levels, outperforming quercetin. Additionally, acute toxicity experiments confirmed the favorable safety profile of A. Radix. This study demonstrates that A. Radix inhibits tumor cell proliferation through multi-component targeting of the PI3K-Akt signaling pathway, providing new therapeutic targets and theoretical evidence for CRC treatment. Furthermore, it establishes a methodological framework for the modern investigation of traditional Chinese medicine formulations.