The importance of electronic structure evolutions and reconstitutions is widely acknowledged for strongly correlated systems. The precise effect of pressurized Fermi surface topology on metallization and superconductivity is a much-debated topic. In this work, an evolution from insulating to metallic behavior, followed by a superconducting transition, is systematically investigated in SnS2 under high pressure. In-situ X-ray diffraction measurements show the stability of the trigonal structure under compression. Interestingly, a Lifshitz transition, which has an important bearing on the metallization and superconductivity, is identified by the first-principles calculations between 35 and 40 GPa. Our findings provide a unique playground for exploring the relationship of electronic structure, metallization, and superconductivity under high pressure without crystal structural collapse.