Abstract: In Chinese judicial practice, evidence standard is confused with proof standard, adequency standard and other standards of fact-finding, which not only deviates from the original meaning and function of Chinese justicial practice, but also leads to the problems like "cramming" conviction. In fact, the evidence standard includes two concrete dimensions: the examination standard of single evidence and the judgment standard of all the evidence of a case, and serves as the minimum evidence threshold for a case to be admitted to trial. It is not only different from the proof standard for the primary decisions of the facts of a case, but also different from the adequency standard for the secondary decisions. The data-based unification of the evidence standard in similar cases needs to go through three steps: formulation of evidence standard in similar cases, data-based modeling, and embedding the data-based evidence standard model into the computer system shared by the public security organ, the procuratorate and the court. However, the data-based unification process may induce legal evidence doctrine, the problems of automatic verification of the admittance criteria of single evidence, as well as system failure caused by the defects of the existing technology.