The present invention relates to a cerebral function state evaluation device, which comprises a brain oxyhemoglobin concentration variation acquiring component, acquiring brain oxyhemoglobin concentrations of a stroke patient, who is in a phase of completing finger-nose and heel-knee-tibia tests under instruction, by applying near-infrared spectroscopic brain imaging technology; a brain functional network constructing component; a typical feature acquiring component; and an evaluation model establishing component. The cerebral function state evaluation device evaluates a patient's motor ability based on brain hemoglobin information. By using the proposed evaluation device, an evaluation result can be given only if a patient completes several required actions. The device is inventive and simple to operate, and subjective factors in the process of the scale scoring can be avoided.