The reform of trial-centered litigation is a fine systematic project. The improvement of any specific system plays the role of “pulling one hair and leading the whole body”. The purpose of supplementary investigation in trial is to reinforce the early investigation and improve the facts and evidence of the case. Supplementary investigation in trial is a typical form of procedure backflow, which leads to the coexistence of investigation and trial, exaggerates the color of investigation centralism, and conflicts with procedural stability, procedural structure, fair trial and other litigation principles, lacking theoretical evidence. This system shows the tendency of functional alienation in practice, which has become an alternative policy to prolong the litigation period, avoid the prosecution risk and end the litigation procedure, and which deviates from the original intention of legislation. For long, it is appropriate to abolish the supplementary investigation in trial, establish and improve the supporting systems such as procuratorial guidance investigation, public prosecution review, withdrawal of prosecution and judicial work evaluation, so as to meet the trial-centered requirements and the value of substantiation of court trial.