Language, as a tool for people's daily communication, has no gender bias itself. With the development of society, the language has changed correspondingly. Language serve as the mirror of society, inevitably reflecting people's minds or ideology as well as the culture and social conditions of a society. While in English, as the mother tongue of many western countries, amounts of gender discrimination expressions are embodied. To some extent, the gender bias toward females serves as the embodiment that females are considerably insignificant and share a low social status. In this paper, the author will analyse the phenomenon of gender discrimination in English language, and find the reason behind it to make people realize the importance of eliminating this phenomenon. If people keep using sexism language unconsciously, it will become the hindrance of the social harmony