In order to reduce the risk of misperception of the facts of the case or the result of the decision due to wrong identification opinions in the judicial appraisal of documents, quality control is particularly important. Firstly, it briefly describes the concept of quality control of judicial appraisal of documents, and organizes the main contents of quality control from three aspects: elements, process and results. Secondly, it analyzes the problems and reasons in the quality control process around “human, machine, material, law and environment”. Finally, we propose to improve the way: first, in the elements of quality control, we emphasize that by improving the qualification audit mechanism of forensic appraisers, implementing the “lifelong learning” system of appraisers, and strengthening the management of instrumentation and environmental factors to improve the quality of appraisal; secondly, for the process of quality control, we mainly discuss the three aspects of evidence management, methodology, confirmation and document report. Second, for the process of quality control, mainly from the management of physical evidence, methodology and paperwork report three aspects of the discussion, which in the management of physical evidence to introduce the “chain of custody” system; Third, for the results of quality control issues, mainly to discuss the improvement of the proficiency testing program; Fourth, in order to strengthen the scientific nature of the court’s examination of evidence, the identification of opinions can be introduced into the “likelihood ratio” system.