The current simulation analysis method for oscillator phase noise is limited by the inherent models， and the resulting noise curve fails to adequately reflect the nonlinear characteristics of the components， thereby posing challenges in guiding practical designs. This paper proposes an approach based on nonlinear models combined with impedance network analysis. A nonlinear component model that is established to ensure the effectiveness of the simulation. Impedance network analysis is applied to derive circuit parameters affecting the system's phase noise. A simulation circuit incorporating the nonlinear model is designed， and the effectiveness of the proposed approach is validated using the advanced design system （ADS） simulation platform. Experimental results indicate that the proposed method aligns more closely with practical design compared to traditional methods. The presented noise optimization scheme is feasible and effective， offering valuable insights for improving phase noise metrics and enhancing overall system performance in practical applications.