Objective To investigate the value of magnetic resonance imaging-proton density fat fraction (MRI-PDFF) and FibroScan in the quantitative evaluation of liver fat content in patients with chronic hepatitis B (CHB). Methods A total of 96 patients with CHB who were hospitalized in Department of Hepatology, The Second Clinical Medical College of Guangzhou University of Chinese Medicine, from February 2017 to July 2020 were enrolled, and all patients were diagnosed based on liver pathological examination. MRI-PDFF and FibroScan were performed before surgery. According to the results of liver biopsy, the patients were divided into non-fatty liver disease group with 44 patients, mild fatty liver disease group with 33 patients, and moderate-to-severe fatty liver disease group with 19 patients. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups, and the Mann-Whitney U test was used for further comparison between two groups; Bonferroni correction was also performed. The receiver operating characteristic (ROC) curve was plotted to analyze the area under the ROC curve (AUC) of hepatic fat fraction (HFF) and controllable attenuation parameters (CAP) in the diagnosis of fatty liver disease and obtain their sensitivities, specificities, and optimal cut-off values. The intraclass correlation coefficient was used to investigate the consistency of MRI-PDFF data. Results The moderate-to-severe fatty liver disease group had a significant increase in MRI-PDFF HFF compared with the non-fatty liver disease group and the mild fatty liver disease group (all P < 0.05), and the mild fatty liver disease group had a significant increase in MRI-PDFF HFF compared with the non-fatty liver disease group( P < 0.05). The moderate-to-severe fatty liver disease group had a significant increase in FibroScan CAP compared with the non-fatty liver disease group and the mild fatty liver disease group (all P < 0.05), and the mild fatty liver disease group had a significant increase in FibroScan CAP compared with the non-fatty liver disease group ( P < 0.05). In the diagnosis of mild fatty liver disease, MRI-PDFF HFF had an AUC of 0.901 ( P < 0.001), a sensitivity of 90.9%, and a specificity of 82.7% at the optimal cut-off value of 5.1%, and in the diagnosis of moderate-to-severe fatty liver disease, MRI-PDFF HFF had an AUC of 0.972 ( P < 0.001), a sensitivity of 96.1%, and a specificity of 89.5% at the optimal cut-off value of 9.7%. In the diagnosis of mild fatty liver disease, FibroScan CAP had an AUC of 0.829 ( P < 0.001), a sensitivity of 77.3%, and a specificity of 78.8% at the optimal cut-off value of 258.5 dB/m, and in the diagnosis of moderate-to-severe fatty liver disease, FibroScan CAP had an AUC of 0.830 ( P < 0.001), a sensitivity of 76.6%, and a specificity of 78.9% at the optimal cut-off value of 285.5 dB/m. Conclusion Both MRI-PDFF and FibroScan can objectively evaluate the degree of fatty liver disease in patients with CHB. MRI-PDFF HFF and FibroScan CAP can be used as noninvasive markers for the quantitative analysis of CHB with hepatic steatosis, and MRI-PDFF HFF tends to have higher diagnostic efficiency.