A gyro output is influenced greatly by the fluctuation of a modulation triangle waveform in integrated optical resonator gyroscopes (IORG). The curve of scale factor K of the gyro with modulation waveform parameters (MWP) is induced. The influence on the output characteristics by MWP distortion is discussed. The relationship between the nonlinearity and MWP undulation is simulated. An IORG experimental system is carried out, and the triangle wave is generated by high-frequency waveform generator. Dynamic range of ±500(°)/s with nonlinearity of 0.96%, and bias drift of 0.69(°)/s with integration time of 1 s over 1 h are obtained. The testing result verifies correctness of the simulation.