Objective To evaluate the combined diagnostic value of combining magnetic resonance diffusion-weighted imaging (DWI) with susceptibility-weighted imaging (SWI) in acute cerebral small vessel disease (CSVD), and to provide reliable technical support for the diagnosis of acute CSVD. Methods A retrospective analysis was conducted on clinical and imaging data from 80 patients with suspected acute CSVD who were admitted in Luoyang Dongfang People’s Hospital from October 2023 to October 2025. Using the comprehensive clinical manifestations, all magnetic resonance imaging (MRI) sequence information, and at least 3-month follow-up results as the“ gold standard”, the detection efficacy of DWI and SWI for acute ischemic lesions and cerebral microbleeds (CMB) was separately evaluated. Furthermore, the clinical diagnostic value of the combined application of DWI and SWI was further analyzed. Results The sensitivity of DWI for detecting acute ischemic lesions was 96.67% (58/60), and the sensitivity of SWI for detecting CMB was 91.30% (21/23). When DWI and SWI were used for combined diagnosis, the overall recognition ability of the diagnostic system for acute CSVD was significantly enhanced, with a sensitivity as high as 98.46% (64/65). The specificity of the combined diagnostic mode remained at 80.00% (12/15). Conclusion DWI and SWI can form an effective complement in the diagnosis of acute CSVD. The combined application of DWI and SWI can further improve the accuracy of the clinical diagnosis results of acute CSVD lesions, providing a reliable imaging reference basis for the formulation of its clinical diagnosis and treatment plans.