Objective The core indicator pool of ischemic stroke (IS) was constructed to provide a basis for the establishment of the core outcome set (COS), so as to improve the consistency of clinical research and evaluation results of traditional Chinese medicine (TCM) treatment of IS. Methods In this study, the mixed methods research (MMR) convergent parallel design was used to carry out qualitative research and quantitative research at the same time, and the two research results were integrated to reach a conclusion. Quantitative research comprehensively collected the multi-source efficacy evaluation indicators of TCM treatment of IS, and carried out descriptive statistical analysis based on frequency theory. Semi-structured interviews were used in the qualitative research, relevant interest groups were selected to understand the evaluation indicators of the IS efficacy of TCM treatment that they were concerned about, and NVivo software was used for in-depth analysis, coding, classification, and extraction of the efficacy indicators. Based on the principle of pillar integration, quantitative and qualitative research results were integrated to construct an element pool of evaluation indexes for the treatment of IS with traditional Chinese medicine. Results A total of 437 standard papers, 71 registered trial protocols, 100 real-world medical data cases and several guideline consensus policy documents were included in the quantitative study, and a total of 314 indicators in the acute phase of IS, 154 indicators in the recovery phase, and 104 indicators in the sequelae phase were extracted. In the qualitative research part, a total of 32 indicators in the acute stage of IS, 34 indicators in the recovery stage and 35 indicators in the sequelae stage were extracted through interviews. Through group discussion and the principle of pillar integration, an element pool of IS ischemic stroke indicators was formed, including 279 IS indicators in the acute stage, 142 indicators in the recovery stage and 91 indicators in the sequelae stage. Conclusion Based on the MMR convergent parallel design, the element pool of the characteristic indexes of the therapeutic effect of IS in TCM was constructed to meet the needs, which provided the preliminary work basis for the construction of the core outcome set of ischemic stroke in the next stage.