Objective Many studies have shown that a high-sugar diet can do a lot of harm to the health of teenagers. As one of the important windows for human to perceive the world, the visual system plays an important role in teenagers’ perception ability. Many studies have confirmed that high-sugar diet can damage visual function, but the current research on the effects of high-sugar diet on visual function mainly focuses on the front of the visual pathway, focusing on the eye system and the optic ganglion, the posterior of the visual pathway, such as the visual central cortex, has not been reported. In order to understand the effect of high sugar diet on visual function, the effect of high sugar diet on central cortex was studied.Methods In this study, we used the behavioral paradigm of GO/NO-GO orientation discrimination task and in vivo multi-channel electrophysiological techniques to explore the effects of high-sugar diet on the primary visual cortex of young mice.Results Behavioral results showed that young mice that had undergone two months of high-sugar diet had a reduced ability to distinguish orientation. The response characteristics of single neurons in the primary visual cortex (V1) were analyzed by electrophysiological techniques. It was found that the ability of orientation tuning of single neurons in the primary visual cortex decreased in mice fed with high-sugar diet, the response variability of neurons increased and the signal-to-noise ratio (SNR) decreased significantly. We further analyzed the changes of SNR and response variability at population level. The results showed that SNR decreased significantly and response variability increased significantly at population level. The results of neuron correlation analysis showed that the noise correlation of primary visual cortex in the high-sugar diet group was significantly up-regulated.Conclusion These results suggest that a high-sugar diet impairs the ability of young mice to discriminate orientation by affecting the receptive field characteristics of individual neurons in the primary visual cortex, as well as the information processing capacity of neuronal populations.