Abstract: Active fiber ring resonator is the key part of a fiber resonant laser gyroscope(FRLG) system. The measurement precision of FRLG is decided by the active resonator performance. The theoretical precision of a fiber resonant laser gyro is changed with different parameters of the active resonator, which can be achieved by including a fiber amplifier in the ring. According to the structure of FRLG, the effect of parameters of active resonator is investigated and discussed in detail. Simulation results showed that the theoretical accuracy is influenced by changing the erbium-doped fiber length and pump power. At the same time, the input power is increased by choosing an appropriate output coupler. The coupling ratio could increase the theoretical precision.