The invention discloses a method for selecting an optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters and relates to the technical field of optical fiber sensing. According to the method, an optical fiber generates linear birefringence under the action of external pressure, so three Stokes parameters of transmitted light are changed, and the three Stokes parameters and the pressure are in a cosine curve relationship. Through optimal selection of the incident light polarization state, the accurate optimization of the sensitivity, linearity and dynamic range of a sensing measurement curve is realized, a sensing performance curve is prevented from falling into low sensitivity and non-linear regionality, and the sensing performance is greatly improved.