The invention provides a preparing method and application of compound hyaluronic acid collagen hydrogel. Particularly, on the condition that a crosslinking material is not contained, hyaluronic acid and collagen are mixed according to a certain proportion, hydrogel can be obtained and has an extremely low content (<0.05wt%) of polyelectrolyte sediment. Moreover, in the obtained hydrogel, the function of hyaluronic acid hydrogel of moisturizing and lubricating the skin can be improved, the function of collagen of guiding tissue repair can be exerted at the same time, larger advantages are shown on the development of medical beauty products, and the compound hyaluronic acid collagen hydrogel can be applied to multiple fields of food, medicine, tissue engineering, cosmetics and the like.