The invention relates to the technical field of medicines for treating burns and scalds, and discloses an external soaking cold compress liquid for burns and scalds and a preparation method thereof. The external soaking cold compress liquid is prepared from the following raw materials in parts by weight of 0.5 part of rock candy, 5-10 parts of mint, 5-10 parts of yellow chrysanthemum, 5-10 parts of rose, 5-10 parts of dandelion, 15-20 parts of radix sophorae flavescentis, 5-10 parts of golden cypress, 10-15 parts of senecio scandens, 5-10 parts of clove, 5-8 parts of borneol, 5-10 parts of fructus cnidii, 5-10 parts of radix stemonae, 0.03-0.05 part of a chlorhexidine acetate solution, and ganoderma lucidum water and mountain spring water serving as a cold compress liquid substrate. The preparation method comprises the following steps of adding rock candy, mint, yellow chrysanthemum, rose, dandelion, radix sophorae flavescentis, golden cypress, senecio scandens, clove, borneol, fructus cnidii and radix stemonae into mountain spring water, mixing and soaking, mixing with ganoderma lucidum water according to a mass ratio of 1: 1, standing for 120 days, and adding the chlorhexidine acetate solution to obtain a finished product. The cold compress liquid provided by the invention has the good effects of removing heat to cool blood, resisting bacteria and diminishing inflammation, easing pain, removing necrotic tissue and promoting granulation, promoting rapid healing of a wound surface and avoiding scars after healing.