Owing to their peculiar structural characteristics and potential applications in various fields, the ultrathin MoS₂ nanosheets, a typical two-dimensional material, have attracted numerous attentions. In this paper, a hybrid strategy with combination of quenching process and liquid-based exfoliation was employed to fabricate the ultrathin MoS₂ nanosheets (MoS₂ NS). The obtained MoS₂ NS still maintained hexagonal phase (2H-MoS₂) and exhibited evident thin layer-structure (1–2 layers) with inconspicuous wrinkle. Besides, the MoS₂ NS dispersion showed excellent stability (over 60 days) and high concentration (0.65 ± 0.04 mg mL⁻¹). The MoS₂ NS dispersion also displayed evident optical properties, with two characteristic peaks at 615 and 670 nm, and could be quantitatively analyzed with the absorbance at 615 nm in the range of 0.01–0.5 mg mL⁻¹. The adsorption experiments showed that the as-prepared MoS₂ NS also exhibited remarkable adsorption performance on the dyes (344.8 and 123.5 mg g⁻¹ of q_m for methylene blue and methyl orange, respectively) and heavy metals (185.2, 169.5, and 70.4 mg g⁻¹ of q_m for Cd²⁺, Cu²⁺, and Ag⁺). During the adsorption, the main adsorption mechanisms involved the synergism of physical hole-filling effects and electrostatic interactions. This work provided an effective way for the large-scale fabrication of the two-dimensional nanosheets of transition metal dichalcogenides (TMDs) by liquid exfoliation.