Abstract Background The shortest distance between the superior mesenteric artery (SMA) or superior mesenteric vein (SMV) and the tumor margin was combined with preoperative serum carbohydrate antigen (CA) 19‐9 and lymph node ratio (LNR) to evaluate joint effects on long‐term survival and liver metastasis in patients with pancreatic head cancer after radical surgery. Methods This retrospective study included 149 patients who underwent pancreaticoduodenectomy for pancreatic head cancer at Harbin Medical University Tumor Hospital from May 2011 to March 2021. The preoperative serum CA 19‐9 level and LNR were combined with the SMA or SMV distance. The joint association between long‐term survival and postoperative liver metastasis was evaluated. Results Based on the receiver operating characteristic curve of postoperative liver metastasis or long‐term survival, the optimal cut‐off values of SMV distance were 3.1 and 0.7 mm, respectively, whereas the optimal cut‐off value of SMA distance was 10.25 mm. The univariate model identified the liver metastasis score (p