Objective To investigate the expression of hsa_circ_0018574 in colorectal cancer tissues and human colon cancer HT29 cell line, as well as its effect on the proliferation and apoptosis of colorectal cancer cells. Methods The circPrimer 1.2 software was used to draw the circRNA sequence structure. Meanwhile, the circRNA microarray was used to screen differentially-expressed circRNA in colorectal cancer tissues and adjacent tissues, and RNA was extracted from tissue samples. The expression of hsa_circ_0018574 in human colorectal tumors was detected by RT-qPCR. The si-circ_0018574 was transfected into HT29 cells, and the expression of CDK2, CDK4, CDK6, cyclinD1, and cyclinE cyclins were detected by colony formation assay, flow cytometry, and Western blot, respectively. Results The expression of hsa_circ_0018574 in human colorectal tumor tissues was significantly higher than that in adjacent tissues (P < 0.01). Meanwhile, the si-circ_0018574 in HT29 cells could significantly inhibit the proliferation of cancer cells, reduce clone formation and colony formation ability (P < 0.01), and induce tumor cell apoptosis (P < 0.01). The expressions of CDK2, CDK4, CDK6, cyclinD1 and cyclinE cyclins were decreased. Conclusion The hsa_circ_0018574 is highly expressed in colorectal tumors, and si-circ_0018574 could significantly inhibit the proliferation of HT29 cells, reduce cell division, and induce apoptosis.