This paper systematically analyzes the measurement results of soil radon of the Haihe River，Tianjin South，Tianjin North and Cangdong faults，and the activity strength or weakness of the four faults are analyzed and divided in terms of the H value，the association of the M and 珚M values and An value． Through the contrast with the segmentation results of the four faults obtained in the fault exploration，it is found that the two are consistent with each other． At the same time， each method is found to have its limitation． Therefore with the proper selection，soil radon measurements can be a preliminary analysis of fault activity and can serve as a reference for the segmentation of fault activity． The contrast of the targets among the different faults reveals that the measurement results of different faults can not been used for determining the strength or weakness of fault activity among the different faults． In reality，in order to facilitate the analysis of fault activity partition，the measurement line of fault gas should be properly encrypted in intersection vicinity of the detection of the known faults．