Granulation tissue begins to appear 2-3 days after injury. Granulation tissue consists mainly of a large number of newly generated capillaries, arranged in a parallel state, perpendicular to the surface, with the surfaces anastomosing with each other to form a protrusion, which appears to be bright red, finely granular, soft and moist to the naked eye and bleeds easily when touched, but is not painful to the senses. The neoplastic granulation tissue is fibrous cells, scattered between capillaries, with few collagen fibers forming, and consists of varying numbers of inflammatory cells and exudate together. The main function of granulation tissue is to protect the wound surface from infection, and it can play the role of repairing wounds and filling the damaged areas such as tissue skin, and foreign bodies and necrotic areas around the damaged tissue can be absorbed or assimilated.