The invention provides sorting and application of a CD117+AT2R+bone marrow mononuclear cell subset. The CD117+AT2R+bone marrow mononuclear cell subset can be used for preparing medicine for treating myocardial infarction lesion. The CD117+AT2R+bone marrow mononuclear cell subset is separated out of the marrow of a rat suffering from myocardial infarction, and then the transferring, apoptosis, heart protection and other capacities of the CD117+AT2R+bone marrow mononuclear cell subset are stated for the first time through in-vitro experiments and in-vivo experiments. It is illuminated for the first time that CD117+AT2R+BMMNCs has higher expression in marrow of a myocardial infarction group than a sham-operation group, and it is firstly put forward that mainly a CD117+AT2R+BMMNCs subset achieves the treatment function. It is proved through the in-vitro experiments and the in-vivo experiments that cells in the subset have higher stem cell characteristics, high transferring and invasion ability, and the ability of reducing the number of apoptotic myocardial cells and being differentiated into myocardial cells. The function of being superior to the function of the CD117+AT2R+bone marrow mononuclear cell subset for improving the heart function of the rat suffering from myocardial infarction is achieved in vivo, and therefore a better myocardial damage repair curative effect is achieved.