In this paper, the self-nutrition of marsh fertilizer and its application effect on different crops were summarized, and the research progress of biogas slurry in improving walnut quality and yield, preventing and controlling walnut disease, improving physical and chemical properties of walnut soil, and improving soil fertility were reviewed, so as to provide theoretical basis for rational application of biogas slurry in walnut planting and production.Under the premise of ensuring walnut quality, it lays a foundation for planting organic walnut or even higher quality walnut, and promotes sustainable development of walnut industry.