The invention discloses a high-precision stress sensing system based on Michelson interference structure and belongs to the technical field of optical fiber sensors. The main structure of the high-precision stress sensing system comprises a pumping source (1), an optical wavelength division multiplexer (3), an erbium-doped optical fiber (3) and the like. The high-precision stress sensing system uses a sinusoidal signal as a modulation signal, does not generate high-frequency interference, and is reliable in operation, high in sensing precision and wide in application range.