A method for stimulating a brain to form a cognitive reaction image is provided, which includes administrating 11C-isotope labeled glucose to a test recipient closing eyes, exposing the test recipient to visual stimulus, auditory stimulus and cognitive stimulus, respectively, and then monitoring the test recipient by a brain imaging device and collecting brain imaging data to compare variation between actions of the administrated 11C-isotope labeled glucose in the test recipient's brain before and after the test recipient being exposed to the stimulus. The brain images in correspondence with the brain reacting to the visual, auditory and cognitive stimuli are obtained by detecting the metabolic process of the 11C-isotope labeled glucose in brain.