Glass containing nanoparticles is attractive for plasmonics and photonics applications due to the significant optical and band gap merits. In this paper, 30/70 nm Fe3O4@MoS2 core/shell nanocomposites were synthesized with a specific surface area of 70.1050 m2/g. XRD spectra revealed the good crystallization peaks of Fe3O4 and MoS2 at 14.4°, 30.1°, 32°, 35.9°, 43.1°, 50.8°, 57.2, and 62.58°, respectively, and the increases of lattice parameter of Fe3O4 and MoS2 confirmed that there was the reaction between them. The vibrations of FeO bonds (616 cm−1), MoS bonds (~600 cm−1) along with A1g of Fe3O4 and characteristic E12g and A1g of MoS2 were displayed in their FT-IR and Raman spectra, respectively, indicating the good core/shell nanostructure of Fe3O4@MoS2.The influence of different Fe3O4@MoS2 doping amounts to glass-forming ability, structure and properties was evaluated through varies characterizations. Fe3O4@MoS2 doping amount higher than 10% could not form homogenous glassy matrix, but formed the ceramic composed of α-TeO2 and 2H-MoS2 crystallines. FT-IR, Raman and XPS spectra showed the vibration of MoO42−, FeO, PbO4, TeO4, TeO3, BO3 groups in glasses, revealing the big modification on structure and the existence of highest Mo6+ states due to high optical basicity of glass. Glass doped 2%Fe3O4@MoS2 presented good network connectivity with good thermal stability (Tx–Tg = 130°) and largest magneto-optical activity (V = 0.1826 min/G.cm) because of the high field strength and high spin polarizability of Fe3O4, diamagnetism nature of Mo6+ in glass and the narrow band gap of Fe3O4 and MoS2.