Due to recent rapid progress in science and technology, scientific and technological tools have been employed in many disciplines' empirical researches to solve problems. Among them, the eye tracking technology, which detects eye movements to acquire relevant data of testers to figure out specific problems, is widely used in many different fields of research, including research in second language acquisition. Second language acquisition has been a hot topic, and its research can not only contribute to people's understanding of human brain, brain activity and consciousness, but also to foreign language learners' success through descriptions of the second language acquisition process and cognition. Eye tracking technology has made some progress in the field of second language acquisition research, mainly in two aspects, language comprehension (e.g., the cognition process of reading) and acquisition (e.g., vocabulary acquisition). This paper reviews the major relevant literature in recent years and predicts the future development.