The invention discloses a silk degumming method, and relates to the technical field of silk processing. The silk degumming method comprises the following steps: A, injecting water in a refining tank, putting silk in the refining tank, heating to 98 to 100 DEG C, and keeping warm for 10 to 20 minutes; B, after regulating the water temperature to be 95 to 97 DEG C, adding 0.8 to 1.2 g/L of sodium carbonate, and keeping warm for 5 to 10 minutes; C, reducing the water temperature to be 40 to 45 DEG C, adding 1 to 2 g/L of 2709 alkaline protease, and stirring and hydrolyzing for 40 to 60 minutes under the condition that the pH (Potential of Hydrogen) is 9.5 to 9.8; D, washing for 15 to 30 minutes under the temperature of 60 to 70 DEG C, and then washing by cold water. According to the silk degumming method disclosed by the invention, the problem of an undesirable degumming effect of existing silk enzyme degumming is solved.