Interlanguage fossilization is an important topic in the study of second language acquisition, which involves changes and solidifications in the language acquisition process that learners develop while learning a second language. The purpose of this paper is to explore the concept of interlanguage fossilization, its causes and its implications in language teaching and education. This paper firstly introduces the concepts of interlanguage language and fossilization, and then focuses on the causes of this phenomenon, including both intra-individual and external environmental factors. Then, the paper puts the impact of the interlanguage fossilization phenomenon in language teaching and education, and how to prevent or slow down the occurrence of it through effective teaching strategies into discussion. Through an in-depth study of interlanguage fossilization, the language acquisition process of learners could be better understood, thus contributing more effectively to the development of language teaching and education.