Pain is one of the most important sensations in daily life, it is necessary to get the essence and mechanism of pain in pain treatment and control. In this article, the pain was induced through injection of angelica on the left shoulder of 12 volunteers, as placebo-control stimulation, the isotonic saline was injected. And through the spectrum analysis of EEG, the EEG feature, the power percentile of δ ,θ, α, β were extracted during the experiment to study the modulation effect of pain on brain information and central mechanism. The research demonstrated that the δ band energy ratio increased and the θ, α, β band energy ratio decreased after pain stimulation, though the activated areas were not strictly same, they mainly located on the left frontal cortex, left temporal cortex, left parietal cortex, occipital cortex. It indicated that these areas were modulated significantly by pain stimulation.