The aptamer TY04 is a single-stranded DNA. However, its biological function has not been elucidated. Here, we found that TY04 specifically bound to multiple myeloma cells MM.1S, and some membrane proteins on the surface of MM.1S cells constituted the target molecules of TY04. TY04 inhibited the growth of multiple myeloma cell lines, induced cell cycle arrest in mitosis, and resulted in a significant accumulation of binucleated cells. Following TY04 treatment, a concomitant increase in CDK1 and cyclin B1 expression occurred. In addition, TY04 treatment also resulted in a significant downregulation of γ-tubulin. Considering the unique advantages of aptamers, TY04 shows great potential as a drug candidate to treat multiple myeloma.