As a solid waste, titanium-bearing blast furnace slag is discarded in the slag field, which brings the double pressure of waste of titanium resources and environmental pollution to the society. It is of great significance to explore new technology and realize the comprehensive utilization of large amount of titanium-bearing blast furnace slag with full component and high added value. In this work, cement mortar was prepared by replacing standard sand with carbonized high titanium-bearing blast furnace slag (carbonized slag) from Panzhihua steel group as aggregates. The chemical composition, crystallized phase and particle morphology of carbonized slag were characterized by X-ray fluorescence spectrometer (XRF), X-ray diffractometer (XRD) and scanning electron microscope (SEM). The compressive strength and electrical resistivity of cement mortar with different carbonized slag content were tested, and the influence mechanism of carbonized slag on the electrical resistivity was discussed. The results indicated that the compressive strength of cement mortar containing carbonized slag met the requirements of building cement mortar. When the substitution of carbonized slag was 80%, the compressive strength of the obtained cement mortar was 74.7 MPa, which was 26% higher than that of standard cement mortar. With increasing substitution amount of carbonized slag, the electrical resistivity of cement mortar at the age of 3 d and 7 d decreased slowly, while that of cement mortar at the age of 28 d increased first and then decreased. When the cement mortar (28 d age) was wet, the introduction of carbonized slag did not reduce its resistivity. However, when it was dried and the substitution of carbonized slag exceeded 60%, the resistivity was dramatically decreased and lower than that of standard cement mortar. When the stand sand was completely replaced by the carbonized slag, the electrical resistivity of the dried cement mortar was the lowest with a value of 1.7×104 Ω?m, which was 87.5% lower than that of standard cement mortar. Carbonized slag with high titanium content can be used as a candidate material for conductive aggregate to prepare conductive cement-based composites for building heating.