The invention discloses tobacco basal fertilizer and topdressing integrated fertilizer, and a preparation method and application thereof, and belongs to the technical field of fertilizer. The tobacco basal fertilizer and topdressing integrated fertilizer is prepared from three organic fertilizer cakes, potassium humate, controlled release compound fertilizer, monoammonium phosphate, ammonium sulfate, potassium nitrate, potassium sulfate, polyaspartic acid, functional microbial flora, magnesium sulfate monohydrate and boric acid. According to the tobacco basal fertilizer and topdressing integrated fertilizer disclosed by the invention, slow release and controlled release are combined, nutrients are balanced and comprehensive, the demands on the nutrients of nitrogen, phosphorus and potassium in all stages of tobacco plant growing can be met, the soil structure is improved, the labor production cost is reduced, and the economic benefit of flue-cured tobacco planting is increased. In addition, the preparation method of the tobacco basal fertilizer and topdressing integrated fertilizer, disclosed by the invention, is simple in operation, short in technical steps, convenient in application, suitable for industrial production and easy to be popularized in flue-cured tobacco planting and fertilizer application.