Biodegradable medical temperature-sensitive hydrogel and preparing method thereof

The invention discloses biodegradable medical temperature-sensitive hydrogel which is composed of segmented copolymers of 3-arm-PEG-PLGA, wherein the PEG is tribrachia polyethylene glycol, and the molecular weight is 400-50000; the PLGA is a copolymer of lactide and glycolide, the mass ratio of the lactide and the glycolide is 2 to 1-20 to 1, and the mass ratio of the mass sum of the lactide and the glycolide and the tribrachia polyethylene glycol is 1.2 to 1-4 to 1; the temperature-sensitive hydrogel is a solution at a low temperature and converted into gel as the temperature rises, the liquid-gel temperature at which the liquid state is converted into a gel state ranges from 15 DEG C to 35 DEG C, reversibility is achieved, and the rupture strength of the temperature-sensitive hydrogel is larger than 40 mm Hg. The invention further discloses a preparing method of the temperature-sensitive hydrogel. The technology is simple, raw materials are easy to obtain, by controlling the reaction conditions, the gel temperature range of a product can meet the human physiological temperature, the product can have high rupture resistance as well, the reversibility is achieved, the biodegradable function is achieved, no organic solvent is used, and the yield is high.