To solve the long-time problem of "evidence bias" in civil litigation, the Evidence Regulations Promulgated by the Supreme People's Court in 2001 and the Interpretation of the Civil Procedure Law in 2015 all regulate it, and the latter particularly stipulates the document filing obligation system. However, this over-conservative and general system shows quite a few deficiencies in the litigation practice. With judgments as clues, this paper offers an analysis of the current operations of document filing obligation in practice, and points out its deficiencies and explores ways to improve the system by drawing on institutional experiences of other countries.