Discourse markers are a complex pragmatic phenomenon. This paper analyzes the pragmatic functions of discourse markers from both the angles of dynamic discourse and subjective discourse. As ostensive leading markers in communication, discourse markers play a key role in constructing the context of discourse and interpreting the intention of the speaker of discourse. Then, by taking cognitive reference point as perspective, the reason for the existence of discourse markers is analyzed. Cognitive Reference Point Theory has strong explanatory power for pragmatic functions of discourse markers, thus providing a new theoretical framework for the study of discourse markers.