In order to explore the role and expound the mechanism of rehabilitative brain computer interface (BCI)-based training (referred to as the Walk Again Neurorehabilitation protocol) in neurofunctional reconstruction in acute phase of cerebral infarction, the investigators choose non-invasive BCI to study lower limb function of patients with acute cerebral infarction. The investigators evaluate lower limb function, the influence on the central brain functional network and relevant immuno-inflammatory indicators, so that the investigators can explore the therapeutic effect and mechanism in the acute phase of cerebral infarction and provide theoretical bases and feasible guidances for the treatment of post-stroke dyskinesia.