The present study investigated the characteristic of semantic cognition of Uyghur-Chinese bilinguals. The event-related potentials (ERP) technique was used to explore the characteristic of N400 wave and topographic map of difference-waves with "picture-word" semantic priming paradigm. There were significant semantic priming effects on two languages. The average amplitude of N400 was similar in two languages, while average amplitudes of three electrodes (F3, F4, PZ) in Chinese were negative than others. Meanwhile, the activation of topographic map of Uyghur was almost in all regions except occipital lobe, and the degree of activation of Chinese was less than Uyghur, but the activation in parietal and bilateral frontal lobes was higher. In conclusion, the present study suggests that two languages of Uyghur-Chinese bilinguals are all sensitive to semantic priming. The bilateral frontal and parietal lobes participate in language switching. Semantic cognition of two languages in Uyghur-Chinese late non-proficient bilinguals is both completed by bilateral cerebral hemispheres. We have not found obvious lateralization on two languages of Uyghur-Chinese bilinguals.