Due to the lack of explicit word boundary markers, L2-Chinese learners have shown some difficulties in Chinese word segmentation. This study aimed to tackle the possible reasons of L2-Chinese learners’ difficulties in word segmentation: L1-biased processing strategy or developing mental representations of Chinese compound words, or both. In an eye-tracking experiment, high-frequency two-character Chinese compound words were used as targets. These compound words were embedded in sentences where their first component characters with prior verbs were manipulated to be either plausible or implausible, while the whole compound words were always plausible. Sentences were presented in character-spaced or word-spaced style. High-proficiency L2-Chinese learners and native Chinese speakers participated. Results revealed non-native-like patterns of L2-Chinese learners: they holistically processed compound words only in the word-spaced condition, while native speakers did so regardless how sentences were presented. The findings indicated that high-proficiency L2-Chinese learners’ difficulty in word segmentation is predominantly caused by their L1-biased processing strategy.