Abstract: This paper addresses the issue that existing clutter simulation methods for airborne early warning radars cannot reflect the phenomenon where strong main clutter and insufficient phase noise in the transmitted signal lead to an increase in the background noise level in the clear area of the range Doppler spectrum. By analyzing the specific impact of phase noise in the processing procedure, this paper establishes fast-time-domain and slow-time-domain models for airborne early warning radars that incorporate phase noise factors into clutter simulation. A clutter scattering model for airborne early warning radars is constructed, considering multiple factors such as clutter scattering, clutter fluctuation, and spectrum distribution to more realistically simulate clutter characteristics. Through simulation experiments, the paper demonstrates the specific extent to which phase noise degradation affects the increase in background noise in the clear area, verifying the effectiveness of the proposed method. This research provides technical support for the overall design of airborne early warning radars and anti-clutter processing.