In this paper, the research progress of photonic crystal fiber optic gyroscope (PCFOG) is introduced based on the work carried out by Beihang University. In terms of optical fiber development, photonic crystal fibers (PCFs) with a diameter of Φ110 μm for 1550 nm high precision fiber optic gyroscope (FOG) and superfine solid core polarization-maintaining PCFs with diameter of Φ100 μm for 850 nm miniaturized FOG have been designed and fabricated. The batch preparation technology of km-level hollow core photonic crystal fibers has been broken through. In terms of gyroscope applications, the accuracy of the interferometric fiber optic gyroscope with solid-core photonic crystal fibers has reached 0.001 (°)/h, and the application in spacecraft has realized for the first time worldwide to our knowledge. The hollow-core interferometric PCFOG prototype with the prototype accuracy of 0.4 (°)/h has been fulfilled. Meanwhile, the application of hollow-core PCF in resonant fiber optic gyroscope has also been investigated.