Astragaloside IV (AS-IV) has exhibited pivotal anti-cancer efficacy in multiple types of cancer, including colorectal cancer (CRC). Meanwhile, circular RNA (circRNA) circ_0001615 has been reported to be involved in the malignant development of CRC. Herein, this study is expected to figure out the interaction between circ_0001615 and AS-IV on CRC progression. The 50% inhibition concentration (IC50), proliferation, apoptosis, and migration were detected by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and wound healing assays. The expression of related proteins was examined by western blot. Circ_0001615, microRNA-873-5p (miR-873-5p), and LIM and SH3 protein 1 (LASP1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The binding between miR-873-5p and circ_0001615, or LASP1, was predicted by Starbase, followed by verification by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The biological role of circ_0001615 and AS-IV on CRC tumor growth was detected by the xenograft tumor model in vivo. According to the IC50 of AS-IV in CRC cells, the 100 ng/mL AS-IV treatment for 24 h was chosen for the following research: Our data confirmed that AS-IV is a beneficial anti-cancer agent in CRC cells. Furthermore, circ_0001615 and LASP1 expression were increased, and miR-873-5p was decreased in CRC patients and cell lines, whereas their expression exhibited an opposite trend in AS-IV-treated cells. Functionally, applying AS-IV might act as a beneficial anti-cancer effect by downregulating circ_0001615 in CRC cells in vitro. Mechanically, circ_0001615 serves as a sponge for miR-873-5p to affect LASP1 expression. In addition, AS-IV inhibited CRC cell growth in vivo by modulating circ_0001615. Overall, AS-IV could mitigate CRC development, at least in part, through the circ_0001615/miR-873-5p/LASP1 axis. These findings support a theoretical basis for an in-depth study of the function of AS-IV and the clinical treatment of CRC.