Analysis of Political Documents from the Perspective of Register Theory—Analysis of Sustainability Policy for Beijing 2022 Winter Olympic and Paralympic Games

Register theory is one of the important theories of systemic functional grammar.It has strong practicability in discourse analysis.The concept and function of register theory can be analyzed and applied to discourse analysis to dig out more effective interpretation methods.Based on the register theory, this article analyzes the ecological sustainable development policy of the Beijing Paralympic Games from three levels: tone, mode, and field of discourse.In order to explore the register characteristics of such ecological policies, and analyze the text functions and text meanings contained in them.The study finds that political documents will use the words which are related to sustainable development to express the field of discourse, and political documents usually use very formal expression to deliver political points to reader.This study will help readers better understand the meaning of political documents, and also help political texts better convey political ideas and opinions to the public.