Objective To investigate the effects of Circ_DOCK1 on the proliferation, migration and invasion of colorectal cancer cells by regulating microribonucleotide -122-5p (miR-122-5p)/peptidylproamino cis-trans isomerase B (PPIB) axis. Methods The expression levels of circ_DOCK1, miR-122-5p and PPIB in cancer tissues and adjacent tissues of colorectal cancer patients were detected by real-time fluorescence quantitative PCR. Human colorectal cells SW480 were transfected with circ_DOCK1 interfering plasmid (sh-circ_DOCK1), miR-122-5p inhibitor (anti-miR-122-5p) and miR-122-5p mimics (miR-122-5p mimics). The proliferation, migration and apoptosis of colorectal cancer cells were detected by CCK-8 method, scratch test and Transwell test. The targeting relationship between circ_DOCK1 and miR-122-5p was analyzed by bioinformatics and luciferase reporter gene experiments. Results The expression levels of circ_DOCK1 and PPIB mRNA in colorectal cancer tissues were higher than those in adjacent tissues, and the expression level of miR-122-5p was lower than that in adjacent tissues. Compared with the rescue group and NC-circ_DOCK1 group, the expression of circ_DOCK1 and PPIB mRNA in sh-circ_DOCK1 group decreased, expression of miR-122-5p increased, and the A value, cell migration rate and number of transmembrane cells at 48 h and 72 h after transfection decreased (P<0.05), which were no significant difference between rescue group and NC-circ_DOCK1 group (P>0.05). Bioinformatics software predicted that circ_DOCK1 contained a nucleotide sequence complementary to miR-122-5p. The dual luciferase reporter gene experiment showed that the relative activity of the wild-type luciferase reporter plasmid of circ_DOCK1 decreased after transfection of miR-122-5p mimics, and the wild-type luciferase of circ_DOCK1 after transfection of anti-miR-122-5p The relative transcriptional activity of the reporter plasmid increased (P<0.05).Conclusion The expression of circ_DOCK1 is up-regulated in colon cancer tissue, and it can affect the proliferation, migration and invasion of colorectal cancer by regulating the miR-122-5p/PPIB axis. Circ_DOCK1 can be considered as the research direction of molecular targeted therapy for colorectal cancer.