A quantum-dot-based measuring system is disclosed. The quantum-dot-based measuring system includes a laser to emit excitation light, an optical fiber probe including a tail end and a tapered tip, and the tapered tip of the optical fiber probe is attached with one or more quantum dots, and the excitation light is injected from the tail end of the optical fiber probe and emitted from the tapered tip to a sample to be detected, an objective lens to collect optical signal reflected by the sample and a spectrometer to receive the optical signal.