The invention belongs to the chemical field of natural products and in particular relates to an extraction method and an application of moringa oleifera leaf total flavones. The extraction method adopts microwave and ultrasound to synergistically extract the moringa oleifera leaf total flavones, and has the advantages of high efficiency, time saving, energy conservation, low energy consumption, simple operation and good repeatability. Besides, an animal test proves that the extracted moringa oleifera leaf total flavones have a significant treatment effect on hyperuricosuria and Alzheimer's disease. The total flavones provided by the invention can reduce uric acid, and can also reduce cholesterol, triacylglycerol, urea nitrogen, creatinine and xanthine oxidase, reduce the generation of uric acid, directly decompose uric acid, improve the renal function, promote uric acid excretion, and protect multiple levels of blood vessels to reduce uric acid, so that the moringa oleifera leaf total flavones are beneficial for healing of lithemia patients and have a broad medical application prospect.