The present work explored the functions of circ_0070934 in regulating malignant phenotype of colorectal cancer (CRC) cells and its underlying mechanisms. Gene expression data set was acquired based on Gene Expression Omnibus (GEO) database for examining circ_0070934 levels within CRC cells and tissues through quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Kaplan-Meier curve and log-rank test were adopted for assessing CRC patient prognosis based on circ_0070934 level. Functional assays including Cell Counting Kit (CCK)-8, EdU incorporation, Transwell invasion, and scratch assays were conducted to determine CRC cell malignancy. Molecular interactions were predicted using circInteractome and StarBase databases, and validated through luciferase reporter assay. Circ_0070934 was upregulated within CRC cells and tissues, which was related to a dismal prognostic outcome in CRC patients. Knocking down circ_0070934 inhibited CRC cell proliferation, epithelial-mesenchymal transition (EMT), and migration. Further, we identified miR-203a-3p as a target miRNA of circ_0070934, and miR-203a-3p negatively regulated Homeobox A13 (HOXA13) expression. miR-203a-3p/HOXA13 axis mediates the function of circ_0070934 in modulating CRC cell malignancy. These data revealed that circ_0070934 was important for maintaining the malignant phenotype of CRC cells, and circ_0070934 knockdown undermined CRC cell malignancy. Targeting circ_0070934/miR-203a-3p/HOXA13 axis is the promising intervention approach for managing CRC.