Objective: To investigate the predictive value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative perfusion parameters combined with serum miR-6861-5p level in the prognosis of patients with primary liver cancer. Methods: A total of 78 patients with primary liver cancer from January 2022 to January 2024 were retrospectively selected as the research objects. According to the pathological stage, the patients were divided into stage Ⅰ-Ⅱ group (46 patients) and stage Ⅲ group (32 patients). DCE-MRI quantitative perfusion parameters [transport constant (K^Trans), rate constant (K_ep), volume percentage of extracellular space outside blood vessels (V_e)] and serum miR-6861-5p levels were compared between the two groups and patients with different prognosis. The correlation between each index and pathological stage, prognosis of patients and the predictive value of combined detection for prognosis of patients were analyzed. Results: K^Trans, K_ep, V_e and miR-6861-5p in stage Ⅰ-Ⅱ group were lower than those in stage Ⅲ group (P＜0.05). Compared with patients with good prognosis, patients with poor prognosis had higher levels of K^Trans, K_ep, V_e and miR-6861-5p (P＜0.05). The levels of K^Trans, K_ep, V_e and miR-6861-5 p were positively correlated with pathological stage and prognosis of patients (P＜0.05). The area under the curve (AUC) of DCE-MRI quantitative perfusion parameters (K^Trans, K_ep, V_e) combined with miR-6861-5p in predicting the prognosis of patients was 0.929, the Youden index was 0.812, the sensitivity was 95.24%, and the specificity was 85.96% (P＜0.05). Conclusion: DCE-MRI quantitative perfusion parameters and serum miR-6861-5p levels are related to the pathological stage and prognosis of patients with primary liver cancer. Combined detection has certain predictive value for the prognosis of patients.