A selective and sensitive method for detecting rutin using MoS2 quantum dots (QDs) as a fluorescent probe is reported in the paper, a one‐step hydrothermal synthesis method was used to prepare MoS2 QDs. The synthesized MoS2 QDs had good stability and water solubility, and the fluorescence of MoS2 QDs was quenched by rutin due to the inner filter effect. There was a good linear relationship between the intensity of MoS2 QDs and rutin concentration ranging from 5.0 × 10−7 to 3.2 × 10−5 mol/L with a detection limit of 3.5 × 10−7 mol/L. MoS2 QDs showed temperature‐dependent fluorescence that had an excellent linear relationship between 20 and 80°C. Therefore MoS2 QDs can be used as specific fluorescence sensors for selection of rutin and for temperature sensing.