Objective To explore the diagnostic value of multiple b value DWI (MBDWI) sequence of 3.0T MRI in benign and malignant breast lesions. Methods A total of 106 cases of female patients with breast lesions and 60 cases of healthy examiners in our hospital from March 2015 to March 2018 were examined by MRI routine scanning and MB-DWI. The pathological examination results were taken as "gold standard" to analyze the proportions of standardized apparent diffusion coefficient (ADCstandard), ADCfast, ADCslow and fast-diffusion (ffast) in benign and malignant lesions and normal breast tissues and the diagnostic value of various parameters for benign and malignant breast lesions. Results Among 106 patients, 61 cases (57.55%) were benign lesions with 36 cases (33.96%) of fibroadenoma, and 45 cases (42.45%) were malignant lesions with 23 cases (21.70%) were non-special type invasive carcinoma. There was no statistically significant difference in the distribution of benign and malignant nodules (P>0.05). There was no significant difference in the distribution of signal features on T1WI and T2WI between benign and malignant breast lesions (P>0.05). ADCslow, ffast, and ADCstandard were decreased successively while ADCfast was increased successively in normal breast, benign breast lesions and malignant lesions (P<0.05). The AUCs of various parameters of MB-DWI in the diagnosis of benign and malignant breast lesions from the smallest to the largest were ADCstandard, ADCfast, ffast and ADCslow. Conclusion MB-DWI sequence can reflect the biological behavior of breast lesions from the molecular level, and it has important reference value for the differentiation of benign and malignant lesions, and the ADCslow and ffast have higher diagnostic value.