The URRT can cause great impacts on the deep-well resistivity observation. In this paper we analyzed the resistivity variation and discuss the mechanism by extracting the night data of geo-electrical resistivity in Jiangning Seismic Station. The results show that:①the deep-well observation of Jiangning station has good inhibition to surface and shallow interference,and the main source of interference for deep-well observation is the URRT. ②The sudden change of data from 01 to 03 at night is related to the irregular maintenance of the URRT. ③The rapid decline of the deep-well geo-electrical resistivity observation NS(AB=1000m)and(AB=200m)in October 2018may not be related to the metal guardrail of S340 highway,and the earthquake intensity around Jiangning station is obviously enhanced. ④The decrease of the long trend of the deep-well geo-electrical resistivity is consistent with the change of water level in the surrounding deep well,which reflects the change of regional stress adjustment. ⑤The "U" change of the deep-well geo-electrical resistivity EW(AB=200m)before the Anhui Wuwei M_L4.1 earthquake is not related to the newly built S340 highway.⑥There are 5 "U" changes in the deep-well geo-electrical resistivity of Jiangning station,which we believe that it is very likely to be related to earthquakes.