Fecha de publicación: 10/09/2021 Fuente: Wipo Tobacco Agriculture The invention belongs to the technical field of microorganisms, and particularly relates to a potassium-dissolving microbial agent, and preparation and use methods thereof. The potassium-dissolving microbial agent in the invention is prepared from clostridium, pseudomonas, lactobacillus sporogenes, rhizobium, pseudoxanthomonas, burkholderia and aerobacter aerogenes through strain activation, amplification culture, fermentation culture and mixing; the potassium-dissolving microbial agent is applied once in the seedling return stage and the vigorous growth stage of crop growth respectively; and if the concentration of the bacteria is 1*108 cfu/ml, the usage amount of each time is 1L/mu. After the potassium-dissolving microbial agent disclosed by the invention is applied into soil, the population quantity of soil microorganisms can be increased; the content of organic matters in the soil can be increased through the activity and metabolism of the microorganisms in the soil; furthermore, slightly insoluble or insoluble potassium substances in the soil are converted into effective potassium which can be directly absorbed and utilized by crops; meanwhile, the potassium utilization rate is increased; and the use amount of chemical fertilizer is reduced, so that the production cost is reduced, and the sustainable development of agriculture is promoted.