For the purpose of developing high-performance glass-ceramic superionic conductor, the controllable precipitation of LiTi2(PO4)3-like superionic conducting phase in the Li2O–TiO2–P2O5 glass system was studied. Al with B or La co-incorporated LiTi2(PO4)3-based glass-ceramics were prepared by the crystallization of the corresponding original glasses. Compared with the sole Al-incorporated LiTi2(PO4)3-based glass-ceramics, the ionic conductivity shows an increase for the boron co-incorporated one and a decrease for the lanthanum co-incorporated one. Through the further in-depth analysis based on the methods of DSC and X-ray diffractive technique, this opposite change in ion conductivity was ascribed to the alterations of crystallization mechanism together with quantity of crystal phases within the glass-ceramics.. The boron addition promoted the precipitation of LiTi2(PO4)3 phase and restrained the precipitation of second phase. The highest ionic conductivity 1.3 × 10−3 S/cm at 25°C was obtained through the heat treatment of B and Al co-incorporated glassy samples at 900°C for 12 h. These inorganic solid electrolytes have a potential application in lithium batteries or other electrochemical ionic devices.