Currently, legal translation studies focuses more on the micro level translation principles and strategies. The perspective of knowledge construction can promote the doctrinal nature of legal translation studies. By introducing new knowledge, legal translation has led the expansion of legal cognitive mode and the superposition of genealogy of legal knowledge. By the method of diachronic investigation, this article, taking the transformation and development of China’s jurisprudence knowledge as example, expounds the legal translation functioning as knowledge communication and genealogy construction, highlighting that legal translation is an indispensable part of promoting the continuous development of China’s legal knowledge system. As legal knowledge communication is bidirectional, it is necessary to make the comprehensive and strategic planning for translating and communicating China’s original legal knowledge to the world.