The invention belongs to the field of high polymer materials and medical equipment, and particularly relates to a formula and a preparation technology of a submucosal injection sodium hyaluronate solution for an endoscope. According to the formula of the sodium hyaluronate solution, the sodium hyaluronate solution is prepared from sodium hyaluronate, sodium chloride, sodium hydrogen phosphate, sodium dihydrogen phosphate, methylene blue and water for injection. The preparation technology of the sodium hyaluronate solution includes the steps that firstly, sodium chloride is stirred and dissolved in a burdening tank, then sodium hyaluronate is added, temperature is raised to 40 DEG C, and stirring is performed; sodium hydrogen phosphate and sodium dihydrogen phosphate are sequentially added in, and stirring continues; secondly, the pH value of material liquid is measured; the pH value of the material liquid is adjusted to reach 7.0-8.0; thirdly, methylene blue is added and stirred, water is supplemented, and volume is metered; fourthly, filtering is performed through a microfiltration membrane ; fifthly, the mixture is encapsulated in an ampoule or a glass bottle and sterilized with steam at the temperature of 121 DEG C for 15 min, and the submucosal injection sodium hyaluronate solution is obtained. The sodium hyaluronate solution is used for endoscopic submucosal dissection (ESD) and is injected below a gastrointestinal mucous membrane, lesions can be fully swelled, a submucosal liquid cushion is formed, a submucosa and a muscular layer can be effectively separated, and bleeding, perforation and other complications can be reduced while electroexcision is facilitated.