As a semiconducting material with relatively low thermal conductivity, MoS₂ nanoflake has the potential to serve as a modulator for optimizing the performance of thermoelectric (TE) materials. However, the low yield of MoS₂ nanoflakes prepared by conventional methods has constrained the development of MoS₂ optimized TE materials. We propose a mechanical exfoliation method for mass production of MoS₂ nanoflakes using attrition mill. After mixed with La and Nb co-doped SrTiO₃ (SLNT) powder, the MoS₂/SLNT composites are fabricated by spark plasma sintering. It is found that the heterojunctions formed at MoS₂/SLNT interfaces with proper band offset can effectively scatter the low-energy electrons, resulting in enhanced Seebeck coefficient without significantly undermining the electrical conductivity. The power factor of composites is improved when the MoS₂ content is lower than 1.5 vol%. Meanwhile, the thermal conductivity of composites is significantly decreased due to the phonon scattering induced large thermal resistance at MoS₂/SLNT interfaces, which is much higher than that in graphene embedded SrTiO₃ composites. Consequently, a maximum ZT = 0.24 is obtained at 800 K in 1.5 vol% MoS₂/SLNT composite, which is ~26 % higher compared with pristine matrix. This work paves the way for application of TE materials modulated by transition metal dichalcogenides.