Strong and frequent earthquake activities makes the central segment of the Tan Lu Fault Zone (Tancheng—Lujiang Fault Zone) become an important seismic belt in eastern China. The fault zone shows local strong earthquakes, inhomogeneous distribution of weak earthquakes and the presence of non earthquake parts. On the basis of five magnetotelluric sections, comparison analyses are made for deep background triggering earthquakes in the central segment of the fault zone in this text. The results indicate that the fault zone cuts through the whole crust and shows highly heterogeneous crust textures. The common presence of alternation of steeply low and high resistivity zones in the crust sections leads intense neotectonic activities along the fault zone. Three examples of crust electrical textures for ≥Ms 7 earthquakes in the fault zone reveal that the strong earthquakes occurred when middle and lower parts of upper crust have a rigid, high resistivity layer connecting a rigid high resistivity zone on one side or two rigid zones on both sides. In this case, the large, connecting rigid high resistivity zone can accumulate big stress and trigger a strong earthquake. Weak earthquake regions in the fault zone show alternation of steeply soft low resistivity and rigid high resistivity zones, and the latter can accumulate limited stress and lead to weak earthquakes. Aseismic regions in the fault zone correspond to the presence of an extremely thick, soft low resistivity layer that becomes a totally creeping zone. In this case, a rigid high resistivity zone by the side of the extremely soft low resistivity layer is difficult to accumulate any stress and cannot cause any earthquakes. The above comparison analyses suggest that seismic activities along a large active fault zone are closely related to its upper crust electrical texture and rheology.