The mathematical model of the nonreciprocity phase error generation of Sagnac fiber coil under the shock mechanical stress is established based on Hooke′s law and the elastic-optic effect theory. The influence of Young′s modulus of adhesive on the Sagnac fiber coil is discussed. The influence of Young′s modulus of the fiber adhesive on the Sagnac fiber interferometer error is verified by simulation and experiment. The results show that the higher the Young′s modulus of the adhesive is, the more stable the system is.