Objective To investigate the effect of miR⁃17⁃5p on the proliferation and metastasis of colorectal cancer（CRC）cells by regulating MYLIP. Methods The tissues adjacent to the CRCs as well the CRC cell lines SW620，Lovo，Caco⁃2，HT29 and normal colon epithelial cells FHC were collected from the CRC patients. miR⁃17⁃5p inhibitor（as experimental group）and miR ⁃NC（negative control group）were transfected into CRC cells by lipo⁃ some transfection technique. The expression of miR⁃17⁃5p in CRC tissues and cells was detected by RT⁃qPCR，the targeting relationship between MYLIP and miR⁃17⁃5p was detected by double luciferase reporter gene assay. MTT assay was used to detect the proliferation of colorectal cancer Lovo cells，Transwell chamber assay was used to detect the invasion and migration of colorectal cancer Lovo cells and Western blotting was used to detect the expression of MYLIP and EMT（epithelial ⁃mesenchymal transition）related proteins in CRC cells. Results The expression of miR⁃17⁃5p in CRC tissues was significantly higher than that in the adjacent tissues（P < 0.05），and the highest expression of miR⁃17⁃5p was found in Lovo cells of the colorectal cancers（P < 0.05）. Knocking down miR⁃17⁃5p inhibited the proliferation and metastasis of Lovo cells in the colorectal cancers. miR⁃17⁃5p was specifically bound to MYLIP′ s 3′ UTR，and mir ⁃ 17 ⁃ 5p targeted the expression of MYLIP′ s protein. Targeted down ⁃ regulation of MYLIP expression by miR⁃17⁃5p promoted the proliferation and metastasis of Lovo cells in the colorectal cancers. Conclusion miR⁃17⁃5p plays an important role in the occurrence and development of colorectal cancer. It can pro⁃