Emotion recognition is the task of recognizing a person’s emotional state. EEG, as a physiological signal, can provide more detailed and complex information for emotion recognition task. Meanwhile, EEG can’t be changed and hidden intentionally makes EEG-based emotion recognition achieve more effective and reliable result. Unfortunately, due to the cost of data collection, most EEG datasets have small number of EEG data. The lack of data makes it difficult to predict the emotion states with the deep models, which requires enough number of training data. In this paper, we propose to use a simple data augmentation method to address the issue of data shortage in EEG-based emotion recognition. In experiments, we explore the performance of emotion recognition with the shallow and deep computational models before and after data augmentation on two standard EEG-based emotion datasets. Our experimental results show that the simple data augmentation method can improve the performance of emotion recognition based on deep models effectively.