Normalizing is an important process that is widely employed in the industrial production of highly permeable grain-oriented silicon steel (GOSS). This is because it yields a proper microstructure, which is subsequently subjected to cold rolling, primary recrystallization, and secondary recrystallization-annealing. As a result, the sharpness Goss texture can be developed and GOSS posseses excellent magnetic properties. In this study, the influence of normalizing process parameters, including the heating rate, solution temperature, second-stage isothermal holding temperature and period for transformation, and cooling rate, on the resultant microstructures and inhibitors in the normalized GOSS were systematically investigated. Two types of distinct regions exist in the hot-rolled GOSS before normalization: the lamellar carbon-riched region elongated along the rolling direction, which is mainly composed of pearlite, and large ferrite region between the former regions. These two regions are alternately distributed from the subsurface to the center of the steel sheet. During heating and the solution processes, austenitization occurs only in the lamellar carbon-riched regions accompanying carbide dissolution, while no transformation occurs in the ferrite regions. An increase in either the solution temperature to up to 1200^oC or its period to up to 3 min leads to the formation of more austenite. And the widely adopted solution condition of 1120^oC for 3 min cannot dissolve all the formed lamellar carbides in the hot-rolled GOSS, leading to the nonuniform carbon concentration of the formed austenite in different regions. Consequently, some austenite can be retained after most of them transformed into martensite during water quenching. Moreover, all the results on microstructural characterization, in situ dilation experiment, and thermodynamic calculation show that austenitization continues to occur at the second-stage phase transformation temperature (900~950^oC), instead of the commonly believed γ→α phase transformation. Therfore, inhibitor precipitation cannot be promoted by this phase transition. Furthermore, the fine nanosized inhibitors can precipitate in the ferrite region because the inhibitor's solubility is greatly reduced with decreasing temperature and in the pearlite regions accompany with the austenitic-to-pearlite transformation during air cooling below 900^oC. An increase in the heating rate and solution temperature cause additional inhibitors in the hot-rolled GOSS to dissolve during the solution stage and reprecipitate to a fine size during the subsequent cooling. After normalization, the main types of inhibitors are AlN, the composite precipitates of AlN and MnS, and TiN.