Objective: To investigate the value of medical 3D printing in preoperative assessment before precise hepatectomy. Methods: The clinical data of 7 patients with complex hepatic tumors from January 2016 to December 2016 in the Department of Hepatobiliary Surgery of General Hospital of Ningxia Medical University were retrospectively analyzed. Of the patients, 5 cases were male and 2 cases were female, with an average age of 55 years. All patients underwent upper-abdominal CT scan with three-dimensional reconstructions by three-dimensional visualization system (MI3DVS), which were imported into the 3D printer to create the exactly same size printed models of the livers. And then, the anatomical features of the livers were analyzed, preoperative simulations were performed and treatment plans were designed. Results: The 3D-printed liver models for all patients clearly showed the intrahepatic vasculature, anatomical morphology of hepatic and tumor tissues, and the adjoining relationship between the tumor and the intrahepatic vascular structures. The calculated average liver volume was (1 872.2±753.7) mL and median tumor volume was 316.96 mL. According to the results of 3D printing, one patient was not suitable for surgical resection due to portal vein tumor invasion, for whom transarterial chemoembolization was recommended, and all the remaining 6 patients underwent precise liver resection. All the actual surgical procedure was completely in accordance with the preoperative operation planning (6/6). No death occurred during the perioperative period. Conclusion: The medical 3D printing technology can be applied in surgical planning for liver tumors, and has certain guiding significance in preoperative evaluation of accurate liver resection.