With the rapid development of digital communication, emojis have played an increasingly important role in computer-mediated communication (CMC). Although Non-face emojis account for approximately 90% of emoji usage, related research remains relatively scarce. Furthermore, there is limited exploration of the differences in the mechanisms of text processing between Face and Non-face emojis. The aim of this study is to investigate the neural mechanisms underlying the differences in text processing between Face emojis and Non-face emojis. We employed a semantic violation paradigm to analyze the cognitive processes of 28 participants as they processed texts in which emojis replaced words. The experimental materials consisted of 8 target stimuli, each corresponding to 15 text sentences. The results indicate that Non-face emojis elicited a strong N400 effect in incongruent texts, suggesting that Non-face emojis may have higher semantic complexity and can function as substitutes for words. In contrast, Face emojis primarily elicited an LNC component, indicating that they are more likely to be perceived as symbols of emotional expression rather than carriers of explicit semantic information. These results reveal the distinct roles of Face and Non-face emojis in text comprehension, providing new insights into emoji semantics and their impact on language processing.