Fault gouge is a good carrier of fault activity information. Fault activity would be known via analyzing the fault gouge. In this paper, scanning electron microscopy (SEM) was used to observe and analyze the corroded micro morphology and stress trace of quartz of the fault gouges of Tamusu fracture (F2) and Narenhala fracture (F7) in the research area of Tamusu, Inner Mongolia. The results show that: (1) The micro morphology of quartz in fault gouge of F2 is mainly type Ia, type II and type III, while that in fault gouge of F7 is mainly type Ia, type Ic, type Ⅱ and type Ⅲ; (2) The corroded micro morphology of quartz surface of fault gouges of F2 and F7 shows that both faults have experienced multiple stages of activity. The activity time of F2 fault is mainly in late Pleistocene, early Pleistocene and Pliocene, the most active period is in early Pleistocene, the activity epoch of F7 fault is mainly in late Pleistocene, early Pleistocene and Pliocene, the most active period is in late Pleistocene, both F2 and F7 faults have not been active since Holocene. The activity of the faults in the Pre-selected area in the late Quaternary affects the final determination of the favorable area, and the study on the active epoch and movement mode of the faults in the research area is undoubtedly of great practical significance for the future earthquake risk analysis.