As an important part of the China Water Tower，the Yellow River Basin in Sichuan has an important strategic position in the overall ecological security of the Yellow River Basin. To promote the modernization of the harmonious symbiosis between human and nature in the Yellow River Basin of Sichuan，it is necessary to coordinate the ecological protection and high-quality development of the region，and promote the co-governance of ecology and the livelihoods of farmers and herdsmen. This paper constructs an evaluation system for the harmonious coexistence of man and nature，quantitatively evaluates the area，and evaluates the effectiveness of existing problems and related supporting policies，and proposes a path for the implementation of modernization that promotes the harmonious coexistence of human and nature.