Objective To investigate the value of diffusion weighted imaging (DWI) and spectral analysis (MRS) in the diagnosis of brain tumors. Methods He clinical and imaging data of 78 patients with brain tumors confirmed by surgery and histopathology were analyzed retrospectively. All patients underwent magnetic resonance imaging, and diffusion weighted imaging and spectral analysis were performed. The ADC values of different brain tumors and their contralateral normal brain tissues were compared, and the changes of metabolites in different tumors were recorded. Results The average ADC value of meningioma was significantly higher than that of the normal side of regional brain tissue ADC, the difference was statistically significant (t=7.96, P<0.05), the average value of ADC for brain metastases higher than the contralateral normal brain region ADC, the difference was statistically significant (t=4.94, P<0.05), the average ADC value of astrocytomas higher than the contralateral normal area of brain tissue ADC, the difference was statistically significant (t=9.09, P<0.05). There was no significant difference in ADC value analysis between meningioma, brain metastasis and astrocytoma (P>0.05). There was significant difference in ADC value between I~II astrocytoma and III~IV astrocytoma (t=7.18, P<0.05), and the difference was statistically significant (P<0.05). Brain metastasis, meningioma and astrocytoma NAA levels were significantly lower than the level of NAA in normal brain tissues, the difference was statistically significant (P<0.05). NAA/Cho and NAA/Cr in astrocytomas was significantly higher than that of brain metastatic tumors and meningiomas, the difference was statistically significant (P<0.05). Conclusion Magnetic resonance imaging of the brain tumor diagnosis and differential diagnosis of a certain value, the value of ADC itself is not a good identification of solid tumors, the combined application of spectrum analysis technology, combining with conventional MRI can classify the qualitative analysis and the degree of common malignant brain tumors, and provide reference for clinical diagnosis and treatment plan.