Abstract: Based on leveling data across fault of Tan-Lu seismic zone from 1992 to 2016, this paper discussed the vertical deformation feature, used the PCA (principal component analysis) for extracting constructive low frequency information and its energy intensity feature with JTFA (joint time-frequency analysis), investigated the information relation to moderate earthquakes above M_L4.0. The results show that the time curve feature of principal components are consistent with long-range leveling results, northern of study area has strong vertical activity. Strong energy concentration area in the time-frequency distribution maps is corresponding to the occurrence of earthquakes over M_L4.5 in less than one year, which could be applied to mid-long term or long term earthquake prediction of this area.