Epilepsy surgery often depends on the accurate positioning of lesions; however, current positioning methods have some limitations. The electrocorticogram (ECoG) in clinical inspection has a high temporal resolution, but its spatial resolution is below the accepted standard. Based on the neurovascular coupling mechanism in the human brain, we propose a new epileptic foci detection method by detecting cerebral microvascular blood flow with microphotodiodes and ultrasound transducers. The results of experiments conducted on animals show that the light signal on the surface of the cortex has good correspondence with the ECoG signal. The spectra of the ultrasound signal also matches that of the electrical signal within a depth of 1 mm below the cortex. Therefore, we believe that this method can improve the spatial resolution of epileptic lesion detection, and it can potentially be used for depth inspection.