Abstract: Photonic crystal fiber-optic gyroscope(PCFOG) has become an important developing direction of FOG due to its low magnetic sensitivity, good temperature stability, and anti -radiation capability in principle. Researchers have studied a lot on the bias characteristics of PCFOG, however, no work has been done on its scale factor performance. In this paper, the factors that lead to scale factor error of PCFOG were analyzed and the error induced by photonic crystal fiber coil was experimentally tested. The results show that PCFOG has better temperature and radiation stabilities than ordinary FOG. Within a temperature range of -40~+70 ℃, the scale factor repeatability of the PCFOG is 242.310-6 without compensation which is almost half of the conventional FOG; After a total dose of 50 krad (Si) radiation, the scale factor shifts 10910-6 and no notable changes are observed with the repeatability and nonlinearity. Therefore, the PCFOG shows one time better stability than conventional FOG.