A spacecraft running in the space environment would be irradiated by the proton, and the irradiation effects on the most important parts of the optical fiber gyroscope in the spacecraft -the optical fiber ring is the most. In order to investigate the irradiation damage induced by proton irradiation on the Capsule type polarization-maintaining optical fibers made in china, the variation of the transportation power at 1310 nm wavelength is measured by means of situ measurement for the 5 MeV and 10 MeV environments protons irradiation on the Capsule type polarization-maintaining optical fibers made in china. The irradiation induced loss is calculated by us. The Stopping and Range of Ions in Matter (SRIM) software was used to simulate the ionic and displacement damage of 5 MeV and 10 MeV energy protons irradiation on the optical fibers. The O 1s and Si 2p analytic spectrum of the before and after irradiation were obtained by means of X ray photoelectron spectroscopy (XPS). Using the Fourier transform infrared spectrometer (FTIR), we analyzed the before and after irradiation spectrum. The results show that at the 1310 nm wavelength, the rradiation induced loss of the of optical fibers increase with the increasing of the protons fluence due to the increase of the SiOH concentration in optical fiber core. The 5 MeV proton irradiation induced loss is worse than that of the 10 MeV mainly because the more worse displacement and the ironic damage induced by 5 MeV proton at the position of the optical fiber core than that of 10 MeV, i.e., the more amount of SiOH generation.