Objective To analyze the risk factors of synchronous and metachronous colorectal cancer with liver metastases (CRLM). Methods The clinical data of 228 patients with CRLM treated by hepatectomy in our hospital during the period from February to August 2017 were retrospectively analyzed. According to the different time of liver metastasis, the patients were divided into synchronous group (synchronous CRLM, 118 cases) and metachronous group (metachronous CRLM, 110 cases). The incidence of postoperative intrahepatic micrometastases was compared between the two groups, and logistic regression analysis was performed to determine the influencing factors of intrahepatic micrometastases in CRLM. Results The incidence of intrahepatic micrometastasis in the synchronous group [66.10% (78/118)] was significantly higher than that in the metachronous group [41.82% (46/110)] (χ2 =13.53, P<0.05). The differentiation degree of primary tumors, TNM stage of primary tumors, the resection margin width of primary tumors were independent risk factors for intrahepatic micrometastases in CRLM (P<0.05). Conclusion The incidence of intrahepatic micrometastases in synchronous CRLM is higher than that in metachronous CRLM. The differentiation degree of primary tumors, TNM stage of primary tumors, the resection margin width of primary tumors are independent risk factors of intrahepatic micrometastases in CRLM.