An optical detecting apparatus and an operating method thereof are disclosed. The optical detecting apparatus includes a light path module, an actuating module, and a data processing module. The light path module is used to emit a light source to a substance and receive an optical signal generated by the substance reflecting the light source. The actuating module is used to actuate the substance to generate a vibration. The data processing module is used to record and analyze a detected result related to the material properties of the substance and adjust detecting parameters of the light path module and the actuating module respectively.