Pentoxifylline can improve cognitive impairment after ischemic stroke, possibly by improving the level of cerebral blood flow, affecting the content of blood oxygen and metabolic substances in the brain, and then playing a protective role in the transmission of nerve electrical signals, and ultimately improving cognitive function. The patients with cognitive impairment and non-dementia PSCIND after ischemic stroke were randomly divided into two groups. In addition to the basic drugs of ischemic stroke, the patients were given pentothemine sustained release tablets and blank control respectively to observe the effects of pentothemine on cognitive function and neuronal electrical signals in the patients with ischemic PSCIND. It is expected to explore the possible internal biological mechanism by using transcranial Doppler, oxygen-dependent functional magnetic resonance imaging and craniocerebral magnetic resonance pop analysis. Finally, statistical correlation analysis was used to elucidate the specific mechanism of pentoxifylline in improving cognitive function of non-dementia patients with cognitive impairment after ischemic stroke.