Abstract: While green capitalism has emerged as the dominant sustainability paradigm in Western developed countries, achieving certain progress, it ultimately represents unsustainable practice cloaked in environmental rhetoric. Kohei Saito, a new-generation scholar of ecological Marxism, conducts a systematic critique of capitalist sustainability approaches—challenging their authenticity, effectiveness, and thoroughness—before proposing his own innovative "degrowth communism". Saito's examination of the practical dilemma of green capitalism and his conception of the future trends of the sustainable development plan offer valuable insights for China's on-going drive to advance sustainable development strategy and green economic development. However, Saito's theory has its own limitations, such as the overgeneralized application of "degrowth" principles and the misinterpretation of communist development theory, necessitating comprehensive and objective evaluation of his ideas.