The invention belongs to the technical field of food processing and especially relates to a processing method of red sour soup. The processing method comprises the following steps: material selection,soaking, primary pulverizing, primary fermenting, secondary pulverizing, secondary fermenting, conditioning and fragrance increasing. The prepared red sour soup contains rich nutrients and has the functions of promoting the production of the body fluid, quenching thirst, promoting appetite and strengthening the spleen. The red sour soup is cool, refreshing and unique in flavor, and lactic acid inthe sour soup can regulate the microecological balance in the intestinal tracts of animals and human bodies, is beneficial to body health, has the effects of inhibiting growth of putrefaction bacteria in the intestinal tracts and weakening toxin production of the putrefaction bacteria in the intestinal tracts, also has the health-care and medical treatment effects of helping digestion, preventingconstipation, preventing aging of cells, reducing cholesterol, resisting tumors, regulating the physiological functions of human bodies and the like, and has nonnegligible nutritional health-care effects. The red sour soup has high stability of quality and is not liable to generate precipitation, turbidity and other phenomena in long-term storage, and the capsaicin content is stable.