The formation, evaluation and grade division of real-world evidence (RWE) are bottlenecks restricting the in-depth development and scientific application of real-world study methods. This paper briefly reviewed the design grade and evidence grade of clinical medical research, and proposed the key points of evidence grade of real-world clinical research, including emphasizing the comprehensive evaluation of internal authenticity and external authenticity, determining the "starting point" of real-world evidence, and using the real-world evidence quality evaluation method. Based on the internationally recognized "grading of recommendations assessment, development, and evaluation (GRADE)", combined with the classification and characteristics of real-world evidence, a preliminary grading scheme was formed. An example was given to illustrate the grading suggestion.