Objective To observe the changes of CT dynamic contrast-enhanced scan in patients with hepatic cirrhosis (HC) complicated with primary liver cancer (PLC) and analyze its diagnostic value. Methods The data of 125 patients with HC in the hospital from April 2020 to July 2022 were retrospectively analyzed. All subjects underwent histopathological examination and CT dynamic contrast-enhanced scan. The size and distribution of lesions in all patients were counted, and the detection status of lesions in arterial phase, venous phase and delayed phase of CT dynamic contrast-enhanced scan were analyzed. With pathological examination as the gold standard, the diagnostic value of CT dynamic contrast-enhanced scan on PLC in patients with HC, blood perfusion parameters of patients with HC and patients with HC and PLC and the changes of blood perfusion parameters under different liver functions were analyzed.Results A total of 161 lesions were detected among 125 patients with HC, of which 8 were <1 cm in diameter, 53 were 1-3 cm, 63 were 4-5cm and 37 were >5cm. Most of the lesions were located in the liver right anterior lobe (45 lesions) and liver right posterior lobe (69 lesions). 149 lesions were detected by CT dynamic contrast-enhanced scan in arterial phase, with a detection rate of 92.55%. 134 lesions were detected in portal phase, with a detection rate of 83.23%. 142 lesions were detected in delayed phase, with a detection rate of 88.20%. Among 125 patients with HC, 75 cases were with positive PLC and 50 cases were with negative PLC by pathological examination. The sensitivity, specificity, accuracy rate, positive predictive value and negative predictive value of CT dynamic contrast-enhanced scan in detecting HC with PLC were 94.67%, 94.00%, 94.40%, 95.95% and 92.16%, respectively, and its Kappa value was 0.884, which showed high consistency. The HAP and HPI in HC group were significantly lower than those in HC with PLC group while the PVP and TLP were significantly higher than those in HC with PLC group (P<0.05). There were 41 cases of CTP grade A, 46 cases of CTP grade B, and 38 cases of CTP grade C among 125 patients with HC and PLC. The HAP and HPI values of CTP grade A were significantly lower than those of CTP grade B and C (P<0.05), PVP and TLP values were significantly higher than those of CTP B and C (P<0.05), there was no significant difference in HPI value between CTP grade B and CTP grade C (P>0.05). Conclusion CT dynamic contrast-enhanced scan can show multi-directional and multi-angle display of HC lesions, and has a good diagnostic value on PLC. The liver blood perfusion parameters have certain characteristics, and can provide reference for PLC diagnosis and liver function grading